


Prepare for trouble (make it double)

by Anonymous



Series: KnY x FGO dump [2]
Category: Fate/Grand Order, 鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Anime), 鬼滅の刃 | Kimetsu no Yaiba (Manga)
Genre: All/Tanjirou, BAMF Kamado Nezuko, BAMF Kamado Tanjirou, Crack, Dirty Jokes, F/F, Give all the girls to Our Lord and Saviour Gudako-sama, Gudako as Nezuko, Gudako is chaotic, Hijinks & Shenanigans, M/M, Male Protagonist and Female Protagonist are twins, RItsuka as Tanjirou, Reincarnation, story written in semi-notes, the pairing is undecided but trust me its
Language: English
Status: In-Progress
Published: 2019-10-24
Updated: 2019-12-04
Packaged: 2021-01-02 11:49:56
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 9
Words: 19,841
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21161192
Author URL: https://archiveofourown.org/
Summary: Like all the normal human do, Fujimaru Ritsuka and Fujimaru Gudako died. Leaving behind the world they had saved countless time, the world that had nurtured them into what the World and Humanity would recognize as Kings of Servant.Normally, they should have been entered afterlife, became the existences that every deities would fight tooth and nail just to have them. Or at least, joined their late comrades in Throne of Heroes.Yet, it seemed they had forgotten one thing: 'normally' never applied to their life.."...Did we just jinx ourselves?""Yes, yes we did.""Dammit.".Or, the amazing adventure of Kamado "Ritsuka" Tanjirou and Kamado "Gudako" Nezuko.





	1. Chapter 1

**Author's Note:**

> Warning: experiment fic. Very short with minimum description and fast pace story.

**Fujimaru Twin**

It's not secret that Fujimaru twins were eccentric in their own way. Gudako with her chaotic tendencies and constant bad luck and Ritsuka with his endless kindness and Protagonist Luck Rank EX.

Both had Protagonist Charisma Rank EX of course.

It's still a mystery how on earth they died and still enter the circle of reincarnation, considering how vicious deities from every religion possible tried to claim their souls. But, eh, they're Fujimaru Twins. Normal wasn't the right word to describe them.

* * *

**Reincarnation**

Ritsuka found himself reincarnated as Kamado eldest sibling. Gudako was a little bit disappointed that she was still the younger one, but at least she now had four younger sibling to be coddled. Ritsuka just enjoyed being a big brother once again.

* * *

**Legacy**

Both of them learning _Hinokami Kagura_. If they could become strong together, why not? Gudako's hardheadedness and Ritsuka's puppy eyes successfully convincing Tanjuro to let the eldest daughter joined their training.

* * *

**In the Eyes of Father**

Kamado family quickly learning how... unique their eldest daughter was. Shameless, not afraid to do dirty work, could get _very_ excited on particular topic. The only one who could rule over her was her big brother.

"Hahahaha! look at this Tanjiro! It's Neo Armstrong Cyclone Jet Armstrong Cannon!"

"For God's sake--Nezuko, stop making dirty reference in front of our siblings!"

"Boo, Tanjiro-nii you peepeepoopoo!"

"Big Brother, what's pe-pe-po-po?"

"Oh my lord-"

Far on the open side in the house, Tanjuro watched his children making a mess on their backyard with a small sweatdrop.

_Good luck, Tanjiro..._

* * *

**Death**

When their father died, only Ritsuka and Gudako who didn't shed any tears. Instead they stood straight with a determination burning on their eyes, holding hand at each other tight. Hanafuda earrings dangled on their ears; right ear on Ritsuka and left ear on Gudako.

It's the symbol of their family's legacy. The promise between them and their father.

They promised to their father to stay strong for their siblings and recently widowed mother. Not as the first born and second born, but as the oldest brother and the oldest sister.

_(Even if they were no longer twins, they would share the burden together. Like how they used to do._

_That's how Fujimaru Twins work. Together, always.)_

They had survived Grand Order and Lostbelt. Countless hijinks and clusterfucks made by yours truly life and fate.

Conquering life? No big deal.

* * *

**Muzan**

It happened so fast Gudako barely keeping up with what had happened.

One moment they were sleeping and then there's scream followed by a thick scent of blood.

It was her mother's scream.

Then one by one they were being attacked by a monstrous individual, didn't even stop at their desperate plea.

Gudako felt utterly hopeless. This man--no, monster, was clearly not something could be killed easily. It was fast, merciless, and full of hate _hate_ _hate_ and cruelty.

She tried to runaway with her youngest sibling, but no avail. The monster attacked her from behind, slashed her and then killing her baby brother. Gudako barely let out a pained scream before fell into the snowy land.

_Fuckfuckfuckfuck__ it hurts,_ she hissed as her back burning in pain. _Why's so hurt? This is too hurt for a slash wound it hurts hurts hurts hurts __hurts--_

_...ah, thank God Ritsuka doesn't come home tonight... At least, one of us will..._

_veng_ _...e..._

_Onii_ _...chan...._

_..._ _rry_ _..._

The next thing she knew was pitch black.

* * *

**Demon...?**

Something's moving. What's it? It's annoying. I'm still sleepy, goddammit.

_...Wait, it's my body. My whole body is shaking._

_Eh? Why's so pitch black? Why do I locked in sitting position?_

_Don't tell me, it's--_

"eaRTHQUAKE!" Gudako screamed on top of her lung. "IT'S EARTHQUAKE! HELP I CANT MOVE MY LOWER BODY MAYDAY MAYDAY--"

"Gudako!"

The young girl stopped her screaming and looking down at the source of sound. It's a bunch of hairs. A talking hair?

_...Oh. It's Ritsuka! And I'm in the middle of piggyback, silly me._

"Gudako," Ritsuka gently dropped her on the ground with teary eyes. His smile was wide but full of sadness, it broke her heart. "I-I'm glad you're still alive... Oh, you made me so scared back then!"

"R-Ritsuka-nii..." Gudako could feel tears swelled. The tragedy that had fallen slowly dawned upon her. "I-I'm sorry, I couldn't protect them! Even though I am the second oldest, I-"

"U-uu..." Her hand slowly clinged on his haori and then cried. Ritsuka held her tight and let out his tears in silence.

They stayed at the same position until Gudako patted Ritsuka's back gently. "It's alright now," she murmured. Ritsuka complied.

"...What now?" she softly asked. The older man only shrugged helplessly.

"We bury their bodies first," he said. "But after that... I don't know. The killer's scent was too complex, not unlike a shapeshifter, so-" he abruptly stopped his words and scream,

"DUCK!"

* * *

**Demon Slayer**

"Move," the swordman ordered. Ritsuka growled, trying to hide Gudako from his' view. "She is now no longer a human. Don't be fooled by her appearance. She might look okay now, but sooner or later she will succumb into her desire and eat you."

Tick. For some reason, Gudako felt pissed. How could him, a stranger, made an assumption of her?

Giyuu glared at Gudako's who was facing the snow, and said, "Look at her eyes and teeth. Sharp fang, silted pupil. The demon blood got into her system and now she become demon."

_Tick. Tick._

"Gudako will never eat human!" replied Ritsuka hotly. He was too angry to mention her current name, not that both of them minded. "Please, don't kill her!"

"Don't leave yourself so defenseless in front of an enemy!"

_Snap._

"Aaaaargh!" Out of reflex, Gudako threw a rock to Giyuu and snarled. "Stop yelling at my brother! Do you think he doesn't know that!? Well, yeah he is too kind and seriously a degenerate dumbass-"

"Hey!"

"But he's my one and only big brother! Don't bully him you stupid, friendless, emo guy!"

It seemed she hit the sore spot, as the man stunned at her insult. Gudako kept snarling while stood in between. No one bully Ritsuka on her watch!

Ritsuka tugged her tight kimono--hey, it felt so tight now she wondered why--and whispered, "Gudako, stop it, you embarrass me-"

"Can't stop won't stop Ritsuka," The older man groaned at the reference but she didn't care. She had someone to bully, or if she had to, attack. "You said I'm a demon and can't eat anything except human flesh? Watch this! Oi, Ritsuka, pass me your onigiri."

"But it's dir--"

"Oh my god just give it to me or I'll tickle you to death."

_((Meanwhile, Giyuu was contemplating whether the young kid's words are true or not. Looking at their quirky dynamics and how the demon still keeping her sanity intact, maybe, she was..._

_No. Don't be fooled, Giyuu. Remember, she is a demon. An odd demon, but nonetheless a demon. If he let down his guard just a second, it's not guaranteed the young boy will be safe.))_

"--fine! Here!" Ritsuka grumbled as he passed the squashed rice ball. "Have fun eating dirt and wool."

"Awesome!" She grinned at the Demon Slayer. "Now watch this asshole."

Gudako opened her mouth widely and,

munched the food. Happily.

Giyuu could feel his jaw dropped.

"Mmm, good as always!" Gudako held her cheek in delight. "Too bad we can't have fish in winter. Still, it's good!"

Ritsuka sighed in relief as Giyuu lowered his sword. "But, germs..." he lamented.

Gudako gave him a flipping bird. "Sod off. Demon can't get sick. Right, Emo man?"

Giyuu was startled with the sudden question and nod. "...Yes, demon is immune with majority of poison," he murmured slowly. Gudako smiled in triumph.

"Still!"

"Oh, c'mon, stop it!"

Giyuu watched in bewilderment as the two sibling bickered with each other. The demon--no, girl, had shrank back to her normal size. It seemed she didn't realize that.

A stubborn yet kind boy and chaotic yet able to maintain her humanity demon girl...

Maybe, this one was different.

* * *

**Kamado Sibling**

Nezuko--or Gudako, the demon girl who acted and lived like a normal human. She could eat normal food and walk on open sun without any worries. The distinct things that differ her were her silted pupils and inhuman strength.

Tanjiro--or Ritsuka, the boy with kind eyes who might be stronger than most pillar. He wore his emotion on sleeve, but he never hesistated to to cut Demon's head. The brightest student Urokodaki ever had, even more than Sabito. He walked with Sun itself side by side.

She was brain, and he was brawn. She brought chaos, and he brought pacifism.

Together on battlefield, they're utterly terrifying.

* * *

**In the Eyes of Agatsuma Zenitsu**

Kamado siblings were...a bunch of weirdo, to put it mildly.

Oh, it didn't mean Zenitsu didn't love Nezuko anymore. Even though sometimes the young girl was outright terrifying, he's still love her!

But it didn't change the fact that Kamado siblings were truly out of the world.

They said they came from mountain, but how on earth they could fluently speak foreign language? It was both amazing and scary in a way.

It's also weird with how they could keep their head cool in any situation. Nezuko seemed always knew what to do and Tanjiro acted like nothing could ever faze him anymore. Which was, infuriatingly, yes. The oldest son of Kamado family was so skilled he could defeat the drum demon unscathed.

But most importantly, Nezuko. Nezuko really loved to make dirty jokes, much to everyone surprise and Tanjirou's embarrassment, and making references that only Tanjirou could understand.

Yesterday she threw a rock while screaming something sounded like 'yeigh', and suddenly Tanjiro laughed hard he had to lay on the ground.

...also, there's one more that always nagging his brain. Both Nezuko and Tanjirou had a soft sound that resonated with each other, so soft he barely heard it.

It was so harmonic, Zenitsu would have categorized it as one of their uniqueness if it wasn't the sound of a _twin_ produced.

Also there's another faint sound coming from them that was so sharp yet so sad and it made him wanted to cry whenever his ears caught it. It was horrific, full of tragedies, but in the same time full of love.

It was too complex. Too foreign Zenitsu could not decipher what's the meaning of that sound. It's not solely about tragedy and revenge.

It was akin of short but fulfilled journey.

It was a tale, a tale worth of hundreds and hundreds paper.

It was...

_(Family. Comrades. Betrayal. Sacrifice._

_Love._

_War._

_S u r v i v o r . )  
_

...confusing.

Sometimes, ignorance is a bliss.

* * *

**Hashira's trial**

The first thing Ritsuka felt when he woke up was confusion.

Where was he? How long he had been fainted? Where's Gudako? Why he was tied up?

And most importantly, who's these people?

The young Demon Slayer contemplated his current situation while keeping his eyes on those people. Looking at their clothes and eye-catching haori, Ritsuka concluded those people were the famous Pillars.

...wait. Wasn't one of them said he was on trial?

What trial? For keeping Gudako with her even though she was a demon? Even if clearly she wasn't an ordinary demon?

He was too busy with his own thought he barely heard people talking to him. Meanwhile, Sanemi was getting annoyed for being ignored.

"Oi, are you deaf or something? Answer me!"

Ritsuka flinched and immediately stood up straight. "Yes, sir! I heard you clear and sound!"

A silence.

_...Ah_. Ritsuka still stood up, slowly realizing what he had just done. Red started to color his cheek.

"I-I'm sorry..." He apologized and slowly sat back. "It's a force of habit."

Shinobu cocked her head curiously. "'Clear and sound', hm?" she said. "That's the first time I hear that. I wonder what does it mean?"

_Oh, shit. Did i just use modern slang?_ Ritsuka was sweating bullet. "Ah, um, t-that's..."

A loud laughter rang from the wooden box much to everyone's surprise. Ritsuka gave it an exasperated look.

"AHAHAHAHAHAHAHA!"

"Gudako..."

"Oh my god, you--" a wheeze, "--of course you will doze off in the middle of serious moment! What's the last time? Oh, right. You fell asleep when _freakin_' smooching Gawain! Hahahahahahaha!"

Ritsuka tried very hard to ignore all the stares and chose to plead the girl in the box instead. "Gudako please stop you promise me not to talk about it--"

"Ah, I also remember that toilet incident-"

"GUDAKO IN THIS HOUSE WE DON'T EVER TALK ABOUT TOILET INCIDENT."

Her laughter intensified.

_((Gudako held back her dark chuckle as her plan went successfully. Ritsuka might not pay attention at their words, but she did. And boy she pissed as hell. She didn't care if those people talking shit about her, but nobody question Ritsuka's sincerity._

_And so, Gudako took a full advantage of Ritsuka's blunder to break the tense situation. Not only it would picture both of them as harmless, it would made a comical impression._

_Now, what would they do next?))_

* * *

**Oyakata-sama** had arrived to save the day. But it seemed they had to show more to convince them.

Gudako stared at Sanemi who held his wounded hand with proud face, not impressed.

_This smell,_ She took a sniff on air and frowned. _He's a rare blood. Well, it's sure smell interesting, but..._

With a sigh, Gudako took a spare handkerchief and medicine inside her pocket then took an approaching step.

Meanwhile, Sanemi grinned merrily at the sight. Come, demon! Show your true nature!

"Are you a dumbass or what?"

"...huh?"

The white haired man faltered, wasn't expecting the sudden comment. Gudako took the opportunity to patched up his wound and continued, "Do you really think I'm some cheap sparkly vampire who will go feral over some special blood? What am I, Edward Cullen?"

Sanemi was stupefied. What in seven hell was she talking about?

"Vampire?"

"Are you always like this? Wounding yourself, letting others to try to ravish you? Not trying to kinkshame you, but, alright. Wow. Calm your tits darling."

_(Mitsuri had to use her Breath to refrain herself from laughing. Her cheeks almost in the same shade of tomatoes.)_

_Twitch._ "What did you just say?"

"What I'm trying to say is, your inner thirst is showing in case you didn't realize. Ever heard something called 'jack off'?" Gudako made a shaking hand motion.

"You know, something that start with 'M' and ended with 'N'. Twelve characters."

_(Kochou covered her face with shoulders shaking hard. Rengoku's face went red as he started to understand what Gudako implied._

_Usui guffawed. Loudly._

_Gyomei recited his pray a little bit louder while covering Tokitou's ears. Meanwhile, the Mist Pillar already lost in thought.)_

_Twitch. __Twitch._ Sanemi growled at the demonic girl and griped his blade handler hard. "Are you asking for a fight, you damn brat?"

"Oh, it's rough play now? Man, you are really a damn masochist. It's okay, I support you."

_(Giyuu chocked his own saliva. Usui, already gave up keeping his dignity, laughed so hard he had to hold his stomach.)_

On the other side, Ritsuka planted his face to ground while muttering apologies and how sorry he was for Gudako's word. He didn't even realize the Snake Pillar had stopped pinning him down nor hearing his words.

Actually, no one truly paid any attention to him. Most of them were too busy holding their own laughter or just laughing out loud shamelessly.

Ubuyashiki smiled inwardly. He didn't even need to ask his daughter what had happened to know the current situation. The way Gudako endlessly made fun of Sanemi, endless train of laughter, and Ritsuka's muttering already spoke enough.

While he couldn't see anymore thanks to his curse, the leader of Demon Slayer Corps knew those Kamado siblings were anything to but ordinary.

A family that Muzan personally killed by his own hand. Looking that he did it in the middle of snowstorm, it must be related to personal grudge.

Then, a demon born from those family, had strength on par with Twelve Moon, yet able to maintain every single aspect of humanity. It's also interesting to note how often she would mention something odd as if it was norm to say. While it sounded ridiculous sometimes, somehow with that way she could divert or even change how the situation went down.

There's also young child who was the sole survivor of said family genocide. He controlled his action pretty mature for his own age, and chose to pursue a path of demon slayer with his demonic sister on tow. Even though he lacked experience, it's clear as day his swordmanhip was stronger than major people, and without a doubt years later he would be the strongest Demon Slayer. Surpassing the first person who almost slayed Muzan.

A slayer and a demon. The first son and first daughter.

The very first and second person whose future he could not see nor predict.

Maybe, maybe,

this would be the last pieces he had been waited for. Their last and most crucial wheel to meet the fated end of Muzan. Ubuyashiki couldn't wait to see what kind of future Kamado sibling would make.

"Ah, by the way, are you perhaps enjoying BDSM, snake man? The way you tied up my brother is pretty suggestive!"

"GUDAKO I BEG YOU PLEASE SHUT UP FOR A SECOND I SWEAR TO GODS ABOVE-"

...If they could stop making the situation less serious.


	2. Chapter 2

**Summary for the Chapter:**

> Gudako decided to do some (half-assed) explanation. Of course Ritsuka had to help her, because 1) he loved Gudako and 2) he can't refuse her.

"Oyakata-sama...is it?" The said man gave Gudako a affirmative smile. "Can I join my brother too? It's kind of awkward if I go back to my box..."

The pillars stared at her as if she had grown a second head. It is impossible for a demon to walk under sun, and the sun currently still on top of their head. What was she thinking?

Ubuyashiki was surprised too, but nodded nonetheless. He knew that this girl could walk under the sun freely, but he still had a hard time believing it. But, if she truly able to do it, then...

"Of course, do as you like."

"Thank you!" Gudako picked her box and cheerily walked out. Meanwhile, the others watched her stepped to open air with bated breath.

Oblivious with the tense atmosphere, Gudako casually step down and approaching his brother with a big smile. Ritsuka smiled back exasperatedly.

There were several surprised gasp from their audience. They couldn't believe their eyes: a demon who could conquer the sun! It was unheard of--even Muzan didn't able to do it!

"How?" Shinobu couldn't help but blurted. Her healer side screaming in curiosity, wanted to know the secret behind this miracle sight. "How can you able to conquer the weakness of every demon?"

Gudako didn't answer back immediately, starstruck with Shinobu's beauty. "Oh my god a cute girl with purple shade color--ghk!" She gave his brother a stink eye while caressed her bruised side. Ritsuka only gave her a stare that screamed 'stop ogling and focus'.

The older man sighed at his younger sister's antic and gave his superior a look; asking for a permission to answer the Insect Pillar's question. After a quick relying the information, Ubuyashiki nodded back.

"Alright, alright," Gudako coughed at her palm. "Well, for a start I certainly don't know but I think my somewhat mutant gene has a big part on it?"

"Mutant... gene?"

Ritsuka, had a suspicion where this conversation would go down, tugged his sister's kimono. "Gudako." _It's still Taisho era you big __doofus__. Don't use modern terms._

The black with orange's shade colored hair girl nodded rapidly. "Ah, right, um..." She made a thinking noise. "Like... Because our family have a strong connection with Sun, Oni blood don't do much on my body system?"

This got everyone's attention. A family that had strong connection with sun?

"Our family for generations has a tradition called Hinokami Kagura--an offering dance to Hino-kami. And, uh, we kinda have to use Breath to do it? Right, Ritsu--uhhh, Tanjirou?"

"Oh, so you finally decide to back to Tanjirou? After all of this time?"

"Well, excuse me if I'm too used to call you that! And you too, always calling me 'Gudako this', 'Gudako that'. Don't you try to guilty trip me, mister!"

Someone coughed deliberately.

"--Sorry," Ritsuka gathered himself back. "Like what Gu--...Nezuko had said, our family traditions require us to learn Breath, and yes, it's different from other Breath."

"Ho?" The Fire Pillar, Rengoku Kyojurou made a curious noise. "And how do you know that?"

"Efficiency and mass muscle," he answered. "Every Breath required different strength, endurance, and speed; all those factors will ended with different mass muscle and lung's capacity. For example, in order to learn Thunder Breath, they tended to put more power in speed so their legs muscle is more refined than other. So it's not weird if people invent their own Breath that compatible with their body condition: Hashibira Inosuke, Shinobu Kochou-sama, and Kanroji Mitsuri-sama are the best explanation. In other side--"

"Tanjirou. For the love of God. The point."

"--Yes, um," Gudako made an angery noise. Ritsuka couldn't help but sigh. "Okay, okay. So long story short, the Breath our late father has taught us, Fire God Breath Technique, somehow allow us to be the incarnation of Sun."

A stunned silence. Gudako had to bite her lips to hold her laughter.

_What an absurd conclusion. Ritsuka, you are really suck at explaining things._ Gudako sighed affectionately. _But don't worry, I __gotchu__._

"Not in literal way, though. That's too extreme," added Gudako. "What he means is Fire God Breath Technique allow us to make every weapon we hold has the same effect as nichirin blade. You can ask Uru... Urukodashi-sensei?"

"Urokodaki-sensei. It has been 2 years, Nezuko."

"Sod. Off."

"Listen you piece of--"

(Ubuyashiki hitched his breath. _Isn't that ability similar to--?_)

Gudako brushed off Ritsuka's remark and continued her explanation. "So, in conclusion, I theorized that my body--Tanjirou too--has changed into something that suitable to use Fire God Breath Technique. And thus even though I changed into an oni, my blood had rejected most of it. So..."

Much to everyone's surprise and horror, Gudako cupped her breasts and stared at them with serious expression.

Ritsuka palmed his face with two hands, utterly exhausted.

"...Yep, totally felt like Steve Rogers but," Gudako pouted. That little shit. Had a gall to pout. "No big boobies."

Ritsuka couldn't help but sob.

**Notes for the Chapter:**

> Some background bcs wow theres plot???


	3. Chapter 3

**Summary for the Chapter:**

> Gudako-sama is Amazing with capital A. But when it came to combat, Ritsuka is the monster one. 
> 
> No, believe me. He is.

"Hmph!"

"Whoa..." The girls of Butterfly Estate went starry eyed as Gudako kicked the ceramic jar into million pieces with ease. "Gudako-san is really strong!"

"Hm?" Gudako tilted her head at the praise. It's nice to be praised by cute girls, but, some corrections wouldn't hurt. _Eh, this can be interesting._

"But Ritsuka is way stronger, y'know? You should check him when Kirito-ed."

One big question mark appeared on their head.

"Ki...Kirito...ed?"

"Nah, don't think about it too much," Gudako waved her hand. "Just give him two swords and you'll see. He may be a boring dummy thick but when it comes to combat, he's the big brain one."

Those young girls stared at each other confused before nodded. "I don't understand what you mean, but we'll do it!"

"'Atta girl!"

* * *

"So... You three want me to dual-wielding?"

Three heads nodded simultaneously. Ritsuka sighed as he pinched his temple.

"Let me guess, Gudako told you to do this?"

"Eh, um..."

"No, no, it's fine," the older man quickly reassured the younger three with a smile. "I'm just surprised you know I can dual-wielding, that's all."

They sighed in relief. Ritsuka was their first male idol they ever have, and so they didn't want to make him troubled.

Plus, they wanted to see Ritsuka's dual-wielding style. If Gudako said it was worth to see, then it must be super amazing!

They moved to open area on Ritsuka's request. His reasoning was he wanted to use obstacles and since it bounded to become messy, doing outside was much safer and easier to clean. 

They agreed about it without hesitation.

"Ritsuka-san, I've prepared the bamboos!"

"Ritsuka-san, Ritsuka-san! Here's the wooden swords!" The man smiled gratefully at the young girl with pink clips who handed him two wooden sword.

"Thank you," he said. The pink clipped girl blushed and nodded shyly.

"Hm?" Shinobu, who coincidentally passed by the open garden, blinked at the makeshift practice field. "Tanjirou-kun, what are you doing with that?"

Ritsuka looked back at the source of voice. "Ah, Shinobu-san. The girls said that they wanted to see my other sword techniques... Since I also need some exercise, I think it won't hurt make their wish come true."

The Insect Pillar made acknowledging noice. "I see," she hummed. "But is it alright to use wooden sword only? You're supposed to cut the bamboo and using wooden sword is kind of..."

Ritsuka shook his head. "It's alright. With enough sharpness and speed, anything can be cut. That's what my teacher once said to me."

_Is he talking about __Urokodaki__-san? __Tomioka__-san's teacher?_ Something's didn't make sense to Shinobu but she couldn't put a finger on it. Nonetheless, she nodded politely.

"Can I watch, Tanjirou-kun? It seems interesting."

"It's alriー"

"What's this?" From her back, Inosuke and Zenitsu popped in. Smokes puffed out from boar mask's nostrils. "Why Gonpachiro is allowed to hold swords? Why he has two swords!?"

Zenitsu, who was forcibly dragged by Inosuke before, gave the masked man a stink eye. "So noisy," he murmured.

He held a finger to the dumbfounded man. "Oi, Gonpachiro! Are you trying to copy this great Inosuke-sama!?"

"God please gave me strength," murmured Ritsuka and sighed. "Inosuke, calm down. You're making scene. And there's Shinobu-san here too."

At the mention of Insect Pillar's name and a tight lipped smile from the said woman, Inosuke flinched and went docile.

"Thank you, Tanjirou-kun," Shinobu turned her head to the other occupants of Butterfly Estate. "Now, why don't you two join us? You too, Kanao. Come here."

"!" The young tsuguko jumped from her hiding place. Embarrassed that she had been caught, Kanao scooted closer to her master with red face. Shinobu couldn't help but smile at the cute sight.

* * *

Gudako, who's in the middle of snooping some snacks, suddenly jolted.

"Hng," her face become serious with heavy tone and "ゴゴゴゴゴゴ" characters appeared behind her.

"I sense someone has been using their Shounen Protagonist Charm without my knowing! How dare this person steal my spotlight as The Most Awesome Waifu Collector! Unforgisanai!"

...

A long pause.

...

"Meh. Probably it's just Ritsuka."

The atmosphere went normal and her face muscle relaxed back. She went back munching her stolen sweet bun.

Goto, who secretly witnessed the absurd transformation, shook in fear.

* * *

Ritsuka sneezed. _Huh. Somebody must be talking about me._

"Ritsuka-san, are you alright?" Asked the blue clipped girl in worry tone. The other girls stared at him concerned.

The man waved his hand. "Don't worry, I'm alright. Now, why don't you three go to Shinobu-san? You will get hit if you are still here."

"Ah, right! Sorry!" Ritsuka watched as the young servants of Butterfly Estate ran towards their master. It reminded him with puppies meeting their parents.

Adorable.

Ritsuka then took a fighting stance and turned his head to his audience. "Can I start now?"

A chorus 'yes' was their response. The man nodded and took a breath.

_Niten_ _ Ichiーtwo heavens as one,_

_Nitō_ _ Ichiーtwo swords as one._

_...let's dance one more time,_

_ **Niten** _ _ ** Ichi-ryū, ** _

_ **original form** _

_Musashi-chan._

* * *

Their vision exploded into thousand colors. 

There was no sign of him using Breath. He simply breathed, then swing his swords so strong and so fast his hands became nothing but blur.

The next thing they knew was a 'thud' sound and behold, a full set of bamboos had been cut clean with wooden swords.

Whether it was metal or wood, sharp or dull, it didn't matter anymore.

They had no longer meaning in front of inhuman speed.

No one made any sound. They didn't able to do so. 

Ritsuka didn't realize the lack of response and continue practicing his swordmanhip. He kept swinging his swords in rhythm: simultaneously attack and reflect, defending, or simply attacking as marching forward. 

Step after step, attack and reflect, swing your sword as you shorten the distance.

_Trust your instincts._

_Trust your swords. _

_Trust yourself and your _ _comrades_ _ー_

_And cut it!_

Another set of bamboos was cut off in one swift move.

Shinobu silently gulped down her shock and growing anger. This, this strength was the one she had been longing for. The strength she had been thriven to have, yet she couldn't because of her small and delicate posture. 

He didn't even use Breath. He didn't even need Breath Techniques to strengthen him, yetー

_If his swordmanhip is already this good, why bother learning Breath Technique?_ It's clear as day that the swordmanhip he currently used wasn't something to scoff at. The forms he used were orthodox and full of improvement, but that was what made his swordmanhip unique and deadly.

Sometimes, a slayer would be trapped in particular situation where they required to improve or even created another form on spot. Many, many people had died because of this. 

But she couldn't say the same on this. The swordmanhip Kamado 'Ritsuka' Tanjirou used wasー_is_ perfect for that scenario. It didn't matter how you attack and how many weapons you usedーthe most important thing was the result.

_Two swords... One is shorter than other... Wait, isn't thatー_

_Ah_. Purple eyes widened in recognition. 

_I see._

_He is using __niten_ _Ichi__-__ryū__,_ a bead sweat rolled on her temple. _A refined one unlike what has been taught in dojo, no less._ It's as if he learned straight from the founder himself!

Now Shinobu could understand why Ritsuka hid it from public eyes. If the elders of Miyamoto household heard even just a rumour of his ability, they would manhunt him down and everything became more complicated. 

Worst case, they would interrogate him to death of forcibly married him off to their family. 

Learning new swordmanhip was not a choice; it was obligation.

_Am I the only one who realized it now?_ Shinobu pondered. _Or maybe someone else had known it before? _

_Hmmm._

She took another look at the scene in front of her and made a mental note.

_I should ask Tanjirou-kun for more information, then inform Oyakata-sama about this. He will be surprised if he find out one of his slayer is an user of Niten Ichi-ryū. _

_After all, Oyakata-sama is a fan of Miyamoto Musashi. He'll be really surprised finding about this._

"GONPACHIROOOO! TEACH ME HOW TO DO THAT TEACH ME TEACH ME TEACH MEー"

"Inosuke, calm down please. Iー"

"TANJIROU YOU BASTARD WHY THE HELL ARE YOU NEVER USE THIS WHEN FIGHTING DEMON!?YOU COULD HAVE SAVE ME SOONER WITH IT!"

"Zenitsu, for the love of God don'tーcalm down!"

_...or maybe I will do it when those three finished their training._

* * *

Meanwhile, Gudako who had finished demolishing all snacks existed in this manor, giggled herself silly that she received weird look from passed by kakushi.

_I wonder what kind of future Ubuyashiki-san will see after receiving our surprise for him,_ Gudako snickered at the thought. _Will he summon us immediately for more information? Will the future change for better or worse in his eyes?_

_Ah, life. I'm so looking forward for it._

(It's needless to say that today's commotion was nothing but Gudako's surprise for the sickly head of Demon Slayer Corps. Ritsuka had realized it beforehand and played it along.

Gudako is the brain. Ritsuka is the brawn.

Too bad everyone always think the opposite.

Well, it couldn't be helped. Gudako's method are always out of the box, or just pure ridiculous that sometimes Ritsuka had to question her sanity and become her moral police.)

It's always sunny in Butterfly Estate.


	4. Chapter 4

**Summary for the Chapter:**

> Theres a reason why Kamado siblings are too OP.

Throne of Heroes.

Simply put, it's a realm dedicated solely for those people who had achieved great deeds in life. They're spirit who had freed themselves from circle of reincarnation, and could only be called into world by certain method.

They're the special being that considered as last resort to preserve the World. Their existence was so important that it's impossible to summon their real person--especially when multiple universes applied in their world.

They wasn't supposed to have their 'clone' memory. They wasn't supposed to remember anything what had happened when they had summoned in certain events.

Yet, with streak of miracles and the mighty power of yellow-green colored mushroom, they remembered.

They remembered years living as Chaldea's Heroic Spirits. Became servants of a twin, a boy and a girl, who looked too similar with a certain couple from a city started with 'F' and ended with 'i'.

Those twin weren't someone special. In fact, they're nothing but normal human with average ability.

_(Well, if one ignored their chaotic tendencies, but, details.)_

Yet that's what made them special. They knew who and what they were, their limit, and how powerless they were. But like an undying fire, they kept burning and fighting and moving forward to save humanity.

They refused to bow to evil.

They refused to give up.

They refused to let themselves fell into despair and stood up for what they believed.

They're the epitome of [Human]. Weak, trusting, and cunning Human. Weird, kind and chaotic Human.

That's what they are.

Two human who reminded them that Servant are not living weapon. That Servant had emotion too, that Servant derserve to fight and obtain what they wanted as long as it wasn't harmful.

That's what Fujimaru Ritsuka and Fujimaru Gudako are.

_(How couldn't they not fall in love with those two?)_

It was only to be expected for Fujimaru twins entered Throne of Heroes, given countless time they had saved the World from destruction.

The fact that they're the only being who could command hundred and more Heroic Spirits, without had to use command spell no less, only escalated the fact.

...Well, that's what they thought, until it happened.

* * *

"HEROIC SPIRITS WHO HAS CONTRACTED WITH CHALDEA, PLEASE COME TO MEETING ROOM!" An announcement rang thorough the realm of Heroic Spirit.

"I REPEAT, HEROIC SPIRIT WHO HAS CONTRACTED WITH CHALDEA, PLEASE COME TO MEETING ROOM! EMERGENCY, EMERGENCY!"

Some sighed tiredly when hearing it. Even when they're no longer in contract with the organization, trouble seemed always follow them.

The fact that Elizabeth insisted to hold Halloween concert and Nero with her annual NeroFest in Throne of Heroes were already troublesome.

Poor Carmilla, she gained Mental Debuff Resistance skill because of exceeded stress.

Several Heroic Spirits only glanced before went back to their activities. Emergency or not, if it's not related to them then no need to come.

"EMERGENCY! IT'S ABOUT OUR LATE MASTERS, FUJIMARU RITSUKA AND FUJIMARU GUDAKO! COME TO MEETING ROOM!"

_What in seven hellー_

Once 'Fujimaru' was mentioned, everyone abandoned what they're doing and ran as fast as they could.

Divine being. King. Demi-God. Hero. Soldier. They all ran and ran, some even using their vehicles or horse, until they arrived at the Meeting Room.

_You two have so much explanation to do,_

_Merlin and Gilgamesh!_

* * *

The so-called meeting room was no more than an enormous Colosseum. Usually it's used by Clairvoyance Gang to discuss unimportant things. it's likely they're the one who called them all.

Clairvoyance Gang itself was a group consisted by Heroic Spirits with Clairvoyance skill. Current members were Older Gilgamesh, or Caster Gil, Merlin, and formerly King Solomon until you-know-what happened.

It's not rare for them causing mischief here and there, especially with Merlin's undying love for prank and Caster Gil's constant need of entertainment. That was one of many reason why other Heroic Spirits were skeptic when those two called them all here.

"Alright," The King of Knight, Arturia Pendragon, crossed her hands and glared at two male accross the room. "Now we all are here. Speak. Now. What do you mean by that announcement?"

"Easy, Arturia," Merlin held his open palm up with reassuring smile. "Don't be so uptight now, alright?"

Before she could say anything, other Heroic Spirit butted in. "What happened to my children?" asked The Mystic Slayer, Minamoto-No-Yorimitsu, or simply Raikou for short. She held a worried face. "Are they okay? Will they arrive at Throne of Heroes safely?"

"About that..." Caster Gil pursed his lips. "To tell you the truth, something has happened that prevent Fujimaru Ritsuka and Fujimaru Gudako join us in Throne of Heroes."

"""What!?"""

Everyone voiced their displeasure and murmured to themselves and others. A hand raised among the sea of people. Caster Gil pointed at the hand raised figure without calling the name. It's hard to tell who was the person.

"Is Second Magic user related to this?"

The answer was immediate.

"No," some voiced their disbelief. "For some miraculous reasons, the old Dead Apostles didn't take any part of thisーI have questioned him. He's clean."

No one dared ask him how he do that. No one dared.

Another hand shot up. "What about other Magician?"

"They're all clean, so stop searching searching the black goat."

"Unbelievable," muttered the ex-Eroge Protagonist and the GAR-est of GAR, Emiya. He cupped his mouth and stared disbelievingly at Clairvoyance duo.

"Zelretch the Troll didn't partake in? What in the world just happening?"

Merlin made a knowing sound. _Right, __Emiya__ is his constant victim to be isekai-ed. Of course he's weirded out by this._

"Alright everyone, calm down," Merlin clapped twice. "We haven't told you what will happen to their soul. Let's discuss about it when you get the picture, okay?"

* * *

The respond was expected.

"I CAN'T ACCEPT IT!" Tamamo screamed. "While I am happy Beloved Husbands born into a family that wholly worship me, I can't accept their fate!"

Beside her, Raikou wailed to her palm. "My children! My poor children!" she cried. "Tell me, Mage of Flowers, is there a way for me to go there? There is, isn't it?"

"C-calm down please, I can't--"

"Unacceptable! We, as the First Emperor of China and their Brother in arm, has to nurture them to be the next Emperor!"

"I can hear it... The bell hast called for a name..."

"Unforgivable... How dare that man hurt Mother and Mama... We can't stand it! We need to comfort Mother and Mama!"

"Hmm, since he is practically an immortal... Fufu, I wonder what kind a sound he'll make once I burn him with my fire?"

"Kill! Kill! Kill! Kill!"

"Everyone please calm down!"

The whole situation was nothing but chaotic for a while.

* * *

Arthur Pendragon, the alternate self of Arturia Pendragon, coughed deliberately in the middle of ruin that once was their meeting room. Other Heroic Spirits had calmed down but still radiated murderous aura.

"Have everyone calm down?" Collectives 'yes' and nods answered his question. "Alright. So to sum the situation, both Master are _somehow, for some reason,_ entered circle of reincarnation and reborn into a world that has very weak connection to our universe system. Is that right, Merlin?"

The Magus of Flower nodded silently. Arthur continued his speech.

"According to Merlin and Caster Gil, they will be faced with several misfortunes. Sadly, because the connection between our realm is quite weak, it's impossible for us to aid them. So!" Arthur immediately shouted to prevent another argument broke.

"Anyone have an idea to compensate it?"

Another murmur broke within the crowd. Some wore puzzled expression, and several had visible frustration.

They wanted to aid their precious Masters. Those two didn't deserve facing the tragedies that would happen in the futureーnot on their watch.

Fujimaru twins supposed to be together with them in Throne of Heroes. They supposed to enjoy their well-deserved life after years fighting for World and Humanity.

Sending them into a world full of Demon, as helpless and weak human? Unacceptable!

A hand shot high to the sky. It was Tamamo-no-Mae, wearing determined face.

"I have an idea," she declared. "I don't know if it works though."

Arthur leaned down.

"Elaborate."

* * *

Hino-kami. Or Fire God, for conventional reasons.

Fire God was the divine being that Kamado clan had worship for ages. They even made a dance called _Hinokami_ _Kagura_ to show their dedication and a form of pray to grant their family a protection from any harm.

There was no further explanation about who was this Fire God. There was no lore, no background story, none. Yet Kamado Clan kept worship this godly figure religiously and taught the Hinokami Kagura from generation to generation.

And such, Tamamo, the divine spirit originating directly from the sun goddess Amaterasu, decided to take advantage of it.

"Fire God is just another name from Sun God, yes? Since I AM practically the Sun Goddess herself, I can give them my blessing!"

It's one of many advantages of being Divine Spirit. Even when their worshipper came from another universe, with enough power and faith they could give them a blessing uninterrupted

The chance was slim, but it was possible. And it's not like they're unfamiliar with gambling fate.

_(There's a saying: modern problem required modern solution.)_

And if it succeed...

Of-_fuckin_-course they would abuse the hell of it.

* * *

It worked.

Tamamo sent them a blessing that allowed Fujimaru Ritsuka and Fujimaru Gudako remember their past self and it _worked_.

_"Hahahaha! look at this Tanjiro! It's Neo Armstrong Cyclone Jet Armstrong Cannon!"_

_"For God's sake--Nezuko, stop making dirty reference in front of our siblings!"_

The deities at Throne of Heroes looked at each other before grinned madly.

Oh, they're gonna have so much _fun_ with it.


	5. Chapter 5

**Summary for the Chapter:**

> Gudako showed the world why she is the big brain one.  
And this particular demon was very kinky and no one could convinced her other ways.

**Notes for the Chapter:**

> Infinity Train arc part 1. Im still thonking how to introduce Akaza to Kamado-Fujimaru siblings in most chaotic way.

Ritsuka hummed as he skimmed the paper. It contained basic information about their next mission.

"Infinity train, huh... Gudako, what do you think?"

Gudako munched her nth dango absentmindedly. "More Twelve Moon Demon. One thousand yen."

She placed the money on Ritsuka's open palm. He gave her incredulous stare.

"Gudako, we share the same money. There's no point placing bet with me."

She hushed him. "Hush. Plot convenient."

Ritsuka rolled his eyes and palming his cheek. "This woman, I swear..."

There was a comfortable silence. Ritsuka stared absentmindedly at the vast blue sky and muttered,

"I will blame you if you're right, though."

"Eh," Gudako shrugged. "No biggie."

((Sometimes Gudako wished she could stop making stupid promise with Ritsuka, given her bizarre luck.

King of Idiot. That was she is.))

* * *

Gudako stared at the ticket on Ritsuka's hand, horrified.

Ritsuka stared at the said woman with deadpanned face. 

"It reeks demon blood," the boy said in monotone voice. "The ticket. The train. Reeks of strong demon."

Gudako switched her stare to the famous 'Infinity Train' then back to the ticket. She did it several times before finally opened her mouth.

"Holy shit did I just jinx ourselves."

"Yes," Ritsuka murmured with murderous tone. "Yes you did."

Zenitsu trembled in horror and fright at the mere sound of Tanjirou's voice. _Holy shit holy shit holy shit Tanjirou sounds so scary right now_ _aaAAAAaaAaAAA_ _I NEED TO RUN AWAY RIGHT NOWー_

"W-we will see the train first! Let's go Inosuke you've gotten your ticket right let's goooo!"

"Oi, Bonitsu stop pulling my handー"

"Oh shut up and get moving you damn pig!"

_I'm sorry Nezuko-chan, but your brother really scares me today! But since it is you, he won't do anything right? _

_...RIGHT?_

Gudako held back her curse as she watched their teammates ran away. _Traitor!_

Now its only her and Ritsuka. Gudako raised both of her hands in surrender and mostly fright.

"Shit, Ritsuka I swear I didn't do it on purposeー"

The orange-black haired girl flinched as Ritsuka took a sharp breath. _Oh my God no no no don't tell me he is pissed__ー_

"Gudako."

_Hiiiiii__!!_ Her whole body shook in fright. _He__ totally is!!!_

"Oh, right," Ritsuka smiled sweetly but not reached his eyes. "You still remember our promise, right? My _dear_, _lovely_, little sister?"

"No," Gudako took a step back. "No, no, no. Ritsuka-nii you can't do it please I beg you don't do itー!"

(The thing Gudako fear most was not Beast. Not Goetia. Not Demon Pillar. Not Crypters or Alien God whoever they actually were. Hell, not even Gacha hell and farming hell, although those two came very close with it.

It was, approved by 99.9% occupants of Chaldea, no other than:

Ritsuka's wrath.

Unlike hers that would involve timeline distortion and _always_ ended up building minor singularity, his was rather docile. There were no collateral damage, no messing up with timeline, no sudden event incoming.

But the damage was _severe_.

His disappointed eyes would make you felt like absolute douchebag for eternity. When he sighed, there's a sudden weight that made one cried out of shame and self-loathing.

There's no need to argue. Whatever he said was true and you're notーand that's a _fact_. No matter if you're a king, an inventor, or even a God,

Anyone who dared to oppose his words was worse than Satan itself.

Receiving punishment? That's a mercy. Be grateful you piece of dingus. Grasp that big L and be a good boy/girl/nonbinary/Astolfo/whatever you wanted to describe your gender.)

Ritsuka threw her a pity eyes that invited dread all accross her body. She took another step back, clutching her hair like there's no tomorrow.

"Ritsuka-nii, please," she sobbed. "I--I'll share my snacks with you for a month! Stay still on my box until you ask me to go out!"

"Gudako..."

"Hell, I--I will kill Michael Jackson 2.0 right here right now!"

"..."

"Onii-chan!" Gudako rarely called Ritsuka with such nickname. She only used it only in desperate situation. And for Gudako, this _is_ a desperate moment.

A life or death situation.

"Please, anything but that! Onii-chan!"

"Gudako," The older man stared at her with stern face. Gudako shrieked.

"No Jojo reference for a week."

The anguish scream rang thorough the entire train station.

* * *

Rengoku Kyojurou had heard many things about Kamado Siblings, especially the older one.

Mastering Water Breathing Techniques within two years. Second fastest finishing the Final Test in his generation.

Successfully subjugated Lower Moon Five alone. The only current slayer who had encountered Kibutsuji Muzan after hundred years.

Currently the only one whose nichirin black colored. Rumour said that it's a rare color even back in older generation.

Keeping a demon girl who is his sister. The same demon who could walking under sun, eating human food, refused to eat human, loved and be loved by people around them regardless the race difference.

He admitted, their first meeting at the trial was... Interesting. The way she handled Sanemi's infamous rare blood and explosive temper was something he doubted will be forgotten anytime soon.

Rengoku was still embarrassed whenever he remembered it. Never, never he had met a girl so graceful and so shameless in the time like Kamado Nezuko. While it sure convinced them all that she wasn't harmful, it was still shameless!

((There was a rumour that the quirky demon girl was really skilled in _certain_ aspect. Something involved two or more people hugging not in platonic way and... _uh._

_Uhhhhhh_ _._

Rengoku decided to stop eavesdropping the female kakushis. For his own good and sanity.))

..._Cough_.

Umu. No more flashback.

Why he was recalling all the information he knew about Kamado Sibling? Well, it's because...

"Umu, Kamado-s_hounen_?"

"Yes, Rengoku-san?"

Rengoku contemplated for a moment then asked,

"Why is your sister crying in the box?"

The sobbing sound from the wooden box went noticeably louder. Kamado 'Ritsuka' Tanjirou smiled widely, yet his eyes weren't.

For some reason Rengoku didn't know, it spooked him. Greatly.

"It's your imagination."

Rengoku's smile went stiff hearing the sickeningly sweet tone.

"Butー"

"It's your imagination."

"Kamado-shounenー"

"It's _your_ imagination."

"..." Rengoku glanced at the seat next to him. One of the _kinoe_-ranked Demon Slayer, Agatsuma Zenitsu, furiously gestured him to stay quiet. He looked like he was on the verge of dying by excessive stress.

Well.

Rengoku shook his head and finally back down.

He sighed. "_Yomoya__ da_."

Kamado 'Ritsuka' Tanjirou and Kamado 'Gudako' Nezuko were really lived up the rumour. They're really hard to understand.

...Or maybe it's just his pride refused to admit that he was intimidated by those two.

Oh, well.

* * *

"Uuu... uhuhu... _Sniff_."

Gudako wiped her last tears and finally composed herself. She took a few deep breath and tried to think positive.

_It's okay, Gudako! You can do it! You still can make Jojo reference by narrate it in your head! __Gudako-san_ _daishori__!_

Gudako nodded to herself. She knocked softly in rhyntm to talk with Ritsuka in Chaldea-standard morse code.

'Safe. Out. ?'

There's no answer. Gudako furrowed her eyebrows and tried again.

'Safe. Going. Out. Now. ?'

Silence.

_Huh. Weird. Usually Ritsuka will immediately reply back._ Gudako pondered. _Maybe it's because of the ticket? No, we've disposed it earlier. _

_Or maybe Ritsuka is waiting for the right moment?_ Gudako sticked her ear to the wooden surface and strained her hearing range as much as she could. There were a sound of something being moved and tied up, but that's it. Gudako cursed. _Damn, it's so quiet. I barely can hear what's happening outside. Maybe I should peek..._

As if it was a cue, someone tapped on her box several times. Gudako quickly realized it was a morse code.

'Out. Safe. Need. You.'

_Oh thank god._ Gudako promptly went out from the enclosed space. She noted the extra four people, three was currently fainted and tied up while one was stared at her with tears on his cheek.

It didn't take too much time for her to guess.

"Did you give him an Oscar-worthy motivational speech and one hell of a hug?"

Ritsuka's deadpanned eyes was all she need. He did it.

She glanced at the rope that binding the extra passengers. It was reeked with mystical power. If she had to compare, it had the same energy with chain of the fool albeit weak. "Where do you get that rope?"

"The demon gave it to them. By tying each ends on two people's wrist, one could travel to other conciousness. I simply untie it down," The crying man nodded in confirmation. "Because we had disposed the ticket earlier, I didn't fall asleep like others."

It was a stroke of luck that the man who was in charge of killing him had a slow react, or else Ritsuka would have a difficulty handled the other three.

Gudako made an 'ahh' sound. "I see. So the demon assigned them to kill your mind while you were trapped in dream, thus leaving you in vegetable state?" She nodded in appreciation. "Not bad, not bad. At least this one didn't have terrible background to be sob of so we can kill this one without worries."

"Then, what do you need from me? The demon is on the rooftops, right?"

It wasn't hard to guess it out. The air outside was filled with strong demon's smell. Even by standing several steps from window, she could catch a whiff of it.

Ritsuka went silent for a moment before asking,

"Do you think something is wrong with this train?"

Gudako widened her eyes, quickly caught his implication. She placed her hand on the floor and tried to feel the train.

Something's moving. It's fast.

It's like a river stream. It's,

It's blood.

It was a sound of rushing blood. Then it explained why the floor had some interesting texture when she pressed it down.

It's a muscle.

_Badump_.

_Badump._

_Badump._

Huh. There was heartbeat. It's faint, but it was there.

Where did the sound come from? Hmm. Several meters in front of them.

Then it meant, the whole train was...

"Interesting," Gudako breathed out in giddiness. She couldn't hold back her excitement. How couldn't she? It was her first time riding a living train! The demon had become one with the train!

_We are riding a living Thomas and Friend! But wait, since we are in the middle of the train, and stomach area is in the middle of human body, then it means..._

"We are currently being vore by Thomas the blue train!"

Ritsuka made an disgusted face. "Gudako. I swear to all Gods above," he blanched at the thought.

"It's fucking disgusting. Stop it. Get some help."

Gudako shrugged. "Okay boomer."

"You can'tーwe are practiallyー aaaaaargh!" Ritsuka threw his hand in frustration. "Okay, you win this time. Now tell me where the neck is so we can just go home already."

Gudako snickered at the sight. It was so fun teasing Ritsuka. She could understand why Shinobu loved to make fun of Giyuu all the time.

"It is several meters from here, near charcoal car. Be careful though, it's guarded by demons and stubborn conductor. It seems their demon art is something related to eye contact; their power mainly centered around their eyes. I suggest you to wear eye protector when facing them."

Their enemy was way stronger than Rui, the Lower Moon Five. At least this demon should be a Lower Moon Two, but maybe not an Upper Moon. Their method was careful, but it was still too practical and lack of raw power she had once imagined.

Kibutsuji Muzan was a prideful man who saw strength as above anything. Cunning was not bad, but lacking a raw, destructive power was something different.

_Although, their strength isn't something to scoff of... Probably a Lower Moon One?_ Gudako tilted her head. _Anyway, we still have to protect the other passengers._

"Ritsuka, I'm going to wake up the others before the demon realized. I should burn their ticket, right?" She looked at the dazed black-haired man for a confirmation. The man went startled and nodded vigurously.

"Y-yes, to wake them up you should burn the ticket... Since it's the one that trap them in dream land..."

"Thanks," Gudako lit her demonic flame on her palm and looked at awaiting Ritsuka. "Go. I am certain Inosuke will join you once he finally wake up. Me and others will protect the other passengers. Remember: no eye contact."

Ritsuka nodded and unseathed his sword. "Near charcoal, right? Alright."

"Good luck, Brother."

"You too."

* * *

It was pretty much a success.

Like what Nezuko had said, Inosuke immediately followed his gut and joined Tanjirou to cut the demon's neck. Luckily they had immobilized the conductor and move him to somewhere safe. They had basically destroyed the whole car without leaving anything.

In the other side, Zenitsu and Rengoku took care the eight cars under Nezuko's well-thought command. The fire pillar had to admit it was the most efficient fight he'd ever had. There was no single movement went waste and he barely felt tired even if he had to protect five cars in the same time.

It was a cherry on top that Nezuko had no difficulty assisted them all in fight. Her enormous strength and fire-based demon art was a life-saviour.

Probably Rengoku had to thank the God for let them had Nezuko at their side. Her orthodox wits and ability to find one's weakness was really dangerous; Demon Slayer corps would've been immediately slaughtered just with few steps if she had sided with Muzan.

Kamado Siblings were truly out of the world.

_Umu_, an idea struck his thought. _I should ask __Kamado-shounen__ to be my __tsuguko__!_

**Notes for the Chapter:**

> Just for hindsight, I use Tanjirou and Nezuko when using other characters POV except those two unhinged protags. They still refer each other with their old names, but when in front of others they'll try to use their current name. Keyword: try.  
Some younger ones may or may not call them with their old name since its easier to remember.
> 
> So, quick question:  
Should i kill rengoku lol ive saved him on my other fics sooo should i do the same here?


	6. Chapter 6

**Summary for the Chapter:**

> Akaza the bestest feminist are here. Of course Gudako would do the worst(read: best) first impression ever in history.

**Notes for the Chapter:**

> Warning: mention of kink in sexual activity. R-15-ish.
> 
> I don't even know what Im writing lol

_It's a good choice to send __Inosuke__ to help Ritsuka,_ Gudako grimaced as she pulled fainted Zenitsu from the rubbles. _Thank God they demolished him before he became bigger. It would have been pain in ass to pull emergency crash._

Who would've thought the demon would screech like a dying walrus once beheaded? He even had a gall to explode into tentacles too, damn kinky bastard. Gudako was mildly infuriated.

No, not because it was disgusting. On the contrary, tentacles was one of many her guilty pleasure kink.

It's because it wasn't hot _at all_. No pinkish tentacles, no wiggly wiggly jiggly stretchy sausages, no abomination in a form of sexual monster, nothing.

Just pure, on verge of death, disgusting monster.

_Preposterous! Unbelievable! How dare he misused the greatest culture of Earth! Unforgivable! I swear, I'll remember this as the greatest shame on my life!_

She kicked the body of the train and turned away angrily with a humph.

Hours later, the kakushi who in charge cleaning the area would find a dent in shape of sandals on train's body and they would wonder who the hell did this. Nobody found it out.

((No, Ritsuka didn't have any clue about this nor her kink. And don't tell him either,

Or else he would punish Gudako harder.))

* * *

They barely regrouped before another trouble crashed in front of them. In literal meaning.

No one saw him coming. One second they were in the middle of enjoying their victory, then there was a massive explosive followed by strong presence of demon. They immediately entered defensive position.

_This smell,_ Ritsuka tighten his grip. _It's almost as strong as Kibutsuji Muzan! Don't tell me this is Upper Moon?_

Gudako cursed under her breath. "Fuck, I don't get paid enough for this shit."

"Gudako," The demon girl tensed hearing Ritsuka's tone.

"W-what is it? Wait don't tell meー"

"No Jojo reference for two weeks."

"Why!?"

"The smoke is clearing!" Shouted Kyoujurou, halted any argument that almost happen. "Prepare for battle!"

They waited with bated breath as smoke became thinner and thinner, slowly giving them a clear view of their new opponent.

Ritsuka unconsciously held his breath.

He was a muscular young man with fair skin, decorated with a mass of thick blue lines. He had a short, fluffy pink hair and thick eyelashes. He also wore simple clothes, only short haori that didn't cover his front body and baggy white pants. He didn't even wear any shoes, simply barefooted.

But what had caught their attention was his eyes. A pair of yellow colored eyes; held a kanji of 'Upper Moon Three'.

_Fuck_, Ritsuka gulped. _He is..._

The pale man smirked and threw a punch to Ritsuka, which swiftly he cut it into two with ease. "Hmph!"

Somehow his action only made the demon happier, as he retreated back with a wide smile adorned his face. "Not even use Breath technique, how impressive," he licked the remaining blood from his healing wound. "At first I thought you're just a foolish weakling, but it seems I'm the wrong here."

"What an impressive regeneration and speed... So this is Upper Moon," Kyojurou stood in between two of them. "But I cannot understand why you are attacking a young one like him. Has your moral hit the bottom since you've become a demon?"

The man laughed sharply. "Ha! A good one. But I simply thought he'd just get in a way between you and me, although... Heh,"

He peered at Ritsuka and licked his lips. The young man couldn't help but shudder.

"Sometimes a wolf wears a sheep's skin, isn't he?"

_This guy...!_ Kyoujurou glared harder and veins popped on his temple. Inosuke, who just finished evacuating all the passengers, quickly joined in and stood behind the Flame Pillar. Gudako rightfully stood behind them all, protecting unconscious Zenitsu while hid herself from the Upper Moon.

They all wore tense expression, feeling weary with the Upper Moon who had brought promising disaster to them. 

Except Ritsuka who held a red face and puffy breath.

_Fuck fuck fuck _ _fuuuuuuuuuuck._

Ritsuka closed his eyes and counted one to ten to calm himself down. He failed.

_I'm totally screwed a a a a a _ _aaaaaa_ _ fuckfuckfuuuuー_

Ritsuka jolted as a stray hand landed on his shoulder. "Ritsuka?"

"G-Gudako!" Ritsuka stuttered. "Yeah--um, yeah, I'm okay, I'm okay..."

"..." The black-orange colored hair girl gave him unbelieving stare. "Ritsuka..."

"I'm not lying! I'm--I'm 100 percent absolutely a-ok!"

"Your face is hella red though."

"Ghgk!"

Gudako eyed her one and only brother strangely. _What's wrong with him? The last time he's like this when meeting Gawain of the... Oh. _

_Oh. _

_Oh._

_Oh!_

_OHHHH_ _!_

Gudako snapped her fingers. "You're turned on, aren't you?"

"Tu--!?" Ritsuka faltered with heavy blush adorned his face. "I'm not--!"

"Oh my God oh my God oh my God!" Gudako laughed hard much to Ritsuka's embarrassment. "You really are!"

"G-Gudakooooooo!" Ritsuka wailed with face in the same shade as tomato. He was so embarrassed he wanted to dig a hole and bury himself alive. "I--I can't help it, he is pretty cute! And you are not in the place to comment; I know what you've done with the female kakushis during our stay in Butterfly Estate! Pervert!"

_Oh, now you have done it._ Gudako was more than ready to counter-attack.

"You are the hypocrite one! Acting like a fair and pure maiden all the time, but inside you are no less than wild animal! Have you forgotten the last time we had a new year party? You, in front of my fucking salad, had a honest to God _kinky_ foursome withー"

"LALALALALALALA! CAN'T HEAR WON'T HEAR!"

"COWARD!"

* * *

All the tension on that ground had crumbled into nothingness, leaving a sense of ridiculousness and strange awkward energy. Even Akaza had already lost a will to continue battle.

All thanks to the bickering duo of Kamado Siblings. They were so loud and full of weird words (_is that English?_) they couldn't help but listening.

And boy, it was wild as fuck.

"_ーyou, in front of my fucking salad, had a honest to God kinky foursome withー"_

_"LALALALALALALA! CAN'T HEAR WON'T HEAR!"_

_"COWARD!"_

No one knew what was salad is, what did in the world kinky meant, or what the fuck was foursome.

But Kyojurou knew it must be something shameless. It couldn't be anything except that.

He really wanted to dig a hole right now. 

They argument continued without any indication of stopping, much to everyone's suffering. Zenitsu, who was still unconscious, now the subject of everyone's jealousy.

((Wrong. He had been awaken a moment before the absurd argument broke. Playing dead was now his greatest mistake. Now he was forced to listen with their argument _word by word_ without mercy. 

He was the most suffering here. Someone please help him.))

In other word, their situation now couldn't be described with any words except ridiculous. Strange.

Embarrassing.

_"Stop exposing me you dipshitー"_

_"Then get your balls and fucking make out with that salmon hair guy you cowardー"_

_Salmon... Hair?_ Azaka wondered dumbly. _Are they talking about me? What?_

He knew his pink hair bound to he insulted, but it was his first time to be called as salmon hair. Was it an insult or a praise? Should he feel happy to not being called as a pink haired man for the first time?

_ーNo._ Azaka shook his head furiously. _Don't get distracted, Azaka. You're an Upper Moon, rank Three no less. Stop listening at their stupid argument and attack them. Stop, oi, stop it youー_

"_HE IS AN ENEMY!"_

Azaka once again distracted.

"_WELL, AT LEAST HE IS LEGAL!"_

_"Legality doesn't solve anything!"_

No one wanted to know why legality was brought out to this weird argument, nor they wanted to find out.

No one.

_"HE IS AN ICON! FEMINIST ICON!"_

_"FOR THE LAST TIME, GUDAKO, REFUSING TO EAT WOMAN DOESN'T COUNT AS FEMINIST ICON!"_

_"IT. IS!"_

"How does he know I don't eat woman?" said Azaka accidentally out loud. His stance had lost all of the hostility, only left out one (1) confused demon man.

Kyojurou couldn't answer him right away, as this was also his first time working together with Kamado Sibling. Thus he glanced at Inosuke who visibly shaking in abundant adrenaline.

"What? What!?" Inosuke changed his battle stance into offensive. "Why are you staring at me? Do you want some fight? You wanna fight me, don't you?"

Nope. No hope. No hope at all.

Kyojurou nodded, smiled serenely, and clasped his hand in a form of praying.

_Oh, Gods above,_

_"ALL WOMEN ARE QUEEN!"_

_"IF SHE BREATH, SHE'S A THOT!"_

_""AAAAAAAAAAAAAARRRGGGHHHHHHHHー!""_

_Please let the dawn come faster._

Kyojurou just wanted to go back home _now_.

* * *

In the end, the battle ended without anyone getting hurt. The dawn had already came when Azaka finally got into his sense.

"This time, I'll let you go! Rengoku Kyojurou! Kamado Tanjirou! Next time we meet, I will make sure to turn you into a demon!"

That was he said before ran away into deep forest. They all watched him ran away from the dawn with different emotion flared up within each person.

Rengoku: weary and burning will to be stronger.

Inosuke: hostile and anger, with a sense of pride for winning.

Zenitsu: relief and growing dread.

Ritsuka: utterly tired emotionally and physically to feel anything.

Gudako: smug.

Silence dawned for a moment before Rengoku decided to break it down.

"Let's report this to Oyakata-sama. And Kamado-_shounen_, Nezuko-san, can we talk for a moment?"

Ritsuka sighed tiredly.

"Acknowledged..."

* * *

Gudako twirled two syringes filled with blood of Lower Moon One and Upper Moon Three, whistling eerily. _Two precious bloods, get-chu! __Fufu__, Thank God I've done my research on Twelve Moon Demon._

Unbeknownst to everyone, (sans Ritsuka, of course) Gudako had took advantage over their absurd situation to took a blood sample from distraught Azaka. By lowering his guard, at very least they could take his blood sample or slow him down to let sun rays killed him for good.

But alas, it seemed they had overdid their daily argument.

Yes. Daily. Their stupid argument happened almost everyday and everywhere they literally could have it in any situation.

Hm. Maybe, they died because of it...?

_...nah. It's dumber than that._

_Ah, who cares!_ No one died, they successfully avoid fighting the wild Upper Moon, and Ritsuka had took off her punishment! She could make Jojo reference again! Yay!

Well, it's all thanks to Oyakata-sama who asked him to do so, but details. What's important was the present.

_All's good, and it's all thanks to this Great _ _Gudako-sama__!_

Hurrah for Clairvoyance EX!

* * *

"Ah, Big Brother! Welcome home!"

"I'm home, Senjurou!"

"Sorry for bothering."

Curious, wide eyes blinked at the extra guest. "Big Brother, this is...?"

"Umu!" The current Fire Pillar smiled widely. "Senjurou, please welcome your new Big Brother Tanjirou! Or is it Ritsuka? It's up to you!"

A long silence.

Senjurou dropped his broom with shell shocked face.

"Big Brother, you...?"

_No, no, no. Oh my God Rengoku-sanー_

Ritsuka quietly hid his reddened face with two palms.

"Rengoku-san... It come out wrong..."

No. He wasn't a new member of Rengoku family.

He was simply became Fire Pillar's Tsuguko. That was all.

That's all, dammit.

**Notes for the Chapter:**

> FYI, Ritsuka is the representatiion of FGO JP while Gudako is FGO NA. That's why Gudako has her Clairvoyance EX, while Ritsuka has his Luck EX.
> 
> Don't take it to personal matter aight.


	7. Chapter 7

**Summary for the Chapter:**

> Ritsuka and Gudako had a long chat with late students of Urokodaki Sakonji, Makomo and Sabito.

**Notes for the Chapter:**

> Kinda serious. Idk what im thinking yo
> 
> Im writing this half asleep so sorry if its messy

It had been one year since Ritsuka trained under Urokodaki. For the last test before he allowed Ritsuka to enter Final Selection, he must split a huge boulder with single katana.

Ritsuka didn't mind it. In his previous life, he had undergo lots of training menus personally made by ancient heroes; cutting a boulder with flimsy sword was just one of many.

With enough speed and power, anything could be used as weapon. 

There's nothing couldn't be cut with. What matter most are what's the right sword and who's the right wielder. 

Cutting a boulder that big was not a hard task, at least for Ritsuka. He had been building his mass muscle since tender age of eightーthe first time his father taught him and Gudako Hinokami Kaguraーand training under the ex-Water Pillar had honed his basic skill into advanced level. Breath Form Techniques, Total Focus Breathing, Stance, and moreーRitsuka had memorized, practiced, and adapted all of it into his own style.

Thus, when Urokodaki said he didn't have any to teach him, he truly meant it. He'd already known his newest student might have already surpassed him in several aspects; he just needed more experience to surpass him completely.

If he had to say, Kamado "Ritsuka" Tanjirou was already strong enough to go on tow with rank A- demon. Final Selection would be anything but difficult.

Boulder test was just an excuse. The representation of Urokodaki's unwillingness and fear to send his precious student toc Final Selection, just to lost their life tragically.

Of course, Ritsuka didn't have any clue about it. But it didn't mean he couldn't take a guess; he might not as sharp as Gudako, but he knew how to read the situation. And it wasn't like Urokodaki hid his own personal feelingーfor a man who had a sharp nose like him, he was too easy to read.

Ritsuka wasn't in hurry. A path of swordmanhip wasn't something that should be taken in rush. Sometimes, he needed to sit down and think.

That was why rather than immediately finish the task in one go, Ritsuka chose to take his time observe the boulder instead.

ーOr rather, the spirits that dwelled around it.

They smelled young. Painstakingly young it made his heart ached. They were spirits born from grief and anger, the remaining shards of people whose life had been taken unfairly.

They were children. Children with infinite potential and hopes, yet life didn't give them a chance to let themselves shine like how they supposed to be.

Ritsuka once again took a sniff to identify more. Their blade. Their stance. Their warding mask, their haori, their kimono, their emotions, it's all smelt likeー

Ritsuka wanted to cry.

_Aaah__, _he lamented.

_How could life is this unfair?_

They were, thirteen of them in total, the late students of Urokodaki Sakonji.

Thirteen students who lost their life in Final Selection. Thirteen students who couldn't rest because of their failure, and thus their wandering spirit went back to Sagiri Mountain.

To look after their grieving Master.

To look for another apprentice, another successor to vengeance their death.

Ritsuka knew he wasn't in place to comment, looking back at how messed up his previous life. But, to think his Teacher had suffered such loss like this...

Waiting eagerly for his student to come home, only to hear that they had died...

No wonder he never wanted him to go on Final Selection.

_ーDon't,_ Ritsuka shook his head. Remember what is your goal, Ritsuka. Don't let anger and grief blinded you.

You have to become Demon Slayer.

You have to stop Kibutsuji Muzan.

_You have to help Gudako turn herself back into human,_ he touched lightly the hanafuda earring dangling on his right ear. _Remember__ your promise with Father. _

_Our promise._

Ritsuka took a deep breath and looked at the top of the boulder. The sun had steadily dived back into the end of valley.

The night had came. It's time to face them.

"...I know you're there," Ritsuka spoke slowly. "Please come out... _senpai_."

A silence. Then, a young figure appeared on top of the huge boulder with a thud. He wore a green yukata, patterned with geometric square design of yellow and a darker green together with white haori. His face was covered by a mask that took a shape of fox's face.

"Who are you exactly?" the masked man asked. "How do you know I am here?"

Ritsuka couldn't see his expression, but he could smell the thick tension came from the wandering spirit. He couldn't blame him.

He was a reincarnated person who came from different timelineーmaybe even different world. His origin clearly not belong to this era, and undoubtedly they had realized it.

Furthermore, he was a mage. A mage with high-quality magic circuits. Coincidentally, he knew step-by-step how to ward off spirits in church-approved way.

_Let's just hope there won't be any misunderstanding._

* * *

The newest student of Urokodaki Sakonji was dangerous.

While living beingーdemons includedーcouldn't see what's the big issue, Sabito and others couldn't say the same. They were wraith; souls of dead people that remain attached to this world due to past grudges, regrets and other sorts of unfinished business that they had during life. They're sensitive with things that couldn't be seen with naked eyes.

This man reekedーno, _radiated_ strong odd energy it felt suffocating. Nobody could identify what the energy was, but Sabito could feel the lingering death just by standing face-to-face with him.

It's as if he wasn't already dead. It's as if the man in front of him very much capable to forcibly dragged him to afterlife, even though his regret hadn't paid off.

Even normal exorcist couldn't do the same. They only could harm spirits with malice intent; without evil thought, it's impossible to harm a lingering spirit. It shouldn't be possible.

But it seemed this man had different story.

"Are you an exorcist?" Sabito griped hard the wooden sword on his hand. He had to negotiate with this dangerous man, or else he couldn't take revenge to that damned Hand Demon who had killed his comrades.

Much to his surprise, the young man smiled and shook his head. "I'm not," he said. "I am Kamado Tanjirou, the newest apprentice of Urokodaki-san. Your _kouhai_. All of you.

And like you, I love him."

Sabito tensed at his last word. How did he know he was, together with other twelve spirits here, the previous student before him? _Is he bluffing?_

"And I am Sabito. How do you know I was formerly Urokodaki-sensei's student?"

"Like him, I have strong sense of smell," the young man who called himself Kamado Tanjirou pointed at his nose. "Thanks to this, I can identify all of you: spirits who can't rest after being killed in Final Selection, thus go back to this mountain out of grief and guilt. Thirteen children in total, right?"

Sabito was stupefied with Tanjirou's answer. _Just by __'smelling'__ all of us, he can find that much? That's way stronger than __Urokodaki-sensei's__ nose!_

"Then, what are you?" Sabito once again pushed down. "You are clearly not a normal human. You have strong spiritual energy exceeding normal limit, not counting that it's coming from another realm."

_And I doubt there's any demon has the same absurd power as yours, _was something Sabito wanted to add but since it sounded way too cruel, he didn't say it.

Tanjirou laughed nervously. "W-Well, about that..."

_He hesitates_, Sabito noted. _So he doesn't want anyone to find out his true nature. __Suspicious_.

Sabito wanted to distrust Tanjirou. He was, by all means, not a human nor a demon. An anomaly. Someone who might will threaten Urokodaki if he wasn't careful.

But, when he stared at those eyes...

He couldn't. Can't. And will never can.

There's nothing but kindness and love within Tanjirou's eyes. Just by one look, all of his doubt instantly washed away. Dangerous person wouldn't have such melancholy gaze.

Even if his background was questionable, Kamado Tanjirou was truly earnest with his words.

Could he trust him? Someone whose power came from foreign world? Someone whose motivation and origin still unknown?

Could he?

"As always, you always think too much, Sabito."

The orange haired man was startled and almost fell down. He looked down at the feminine figure who stood beside the boulder. "Makomo!"

Makomo giggled at Sabito's annoyed expression. "You think too much," she repeated. "Ah, I almost forgot. Good evening, Tanjirou-san. My name is Makomo. Please do not worry much about Sabito, he has slight trust issue."

Tanjirou snapped from his daze and bowed to the flower patterned kimono girl. "Good evening to you too, Makomo."

Makomo smiled sweetly before looked back at Sabito with a small pout.

"He loves Urokodaki-sama. I love Urokodaki-sama too, so I know I can trust him. Why can't you do the same?"

"It's becauseー"

"Everyone trust him too."

"ーurk," Sabito couldn't think another excuse and ended up gave in. "Fine, fine! I won't question you again. But!"

Sabito pointed straight at Tanjirou with wooden sword. "I'll recognize you as a man when you can cut this boulder; for now you're no less than ankle bitter in my eyes!"

"Eh?" Tanjirou blinked his eyes numerous time before realized what Sabito had just said. "Ah, um, alright," he nodded and gave them a gentle smile. Sabito felt his chest tightened.

"Can I make one request for you two though?"

* * *

It's amazing how loved Urokodaki Sakonji was. Thirteen wraiths born from dying children, wandered back to this cold mountain as if it was their one and only home. Two of them even gained a semi-corporal body; out of love for their Master and undying will to help current apprentice get stronger.

_No wonder Ritsuka send those two to meet me,_ Gudako stared happily at the pair of wandering spirit. _He knows I also can see them. _

The demon girl noted Sabito's uncomfortable expression and wondering eyes of Makomo. _Trying to guess who I am, aren't you? _

"Good evening, can I help you?" Gudako tried her best not to laugh at their expression. "Sorry I didn't greet you sooner, I was too focused on my meal. You see, the master of this mountain is really good at cooking vegetables, especiallyー"

"I already know that!" shouted Sabito, index finger pointed at her face. His face, no longer hidden behind the warding mask, held a unbelief expression. "The most important thing is why there's a demon in Sagiri Mountain?! Why can you eat human food?! Andーdid you just eat a meal made by Urokodaki-_sensei_?!"

"Oh boy aren't you a talker one," Gudako sighed. "Joy. Oh, by the way, what is your name, my fair maiden?"

Makomo blinked once, and twice, before pointed at herself. "Ah, um, me?" Gudako nodded. "My name is Makomo..."

_Cuuuuuuuute__! _Gudako closed her eyes and basked herself under the cuteness of Makomo. _So __cuuuuuuute__! Her voice! Her little body! __Pettanko__! Dazed eyes! Dreamy and __moe__ voice! _

Gudako quickly composed herself. _Aaah__, how dangerous. I almost get a nosebleed. Baby steps, Gudako. Baby steps. _

She quickly put a charming smile and leaned closer to Makomo.

"Makomo, hm? Such beautiful name, like the owner," She winked at the girl in flower patterned kimono. Gudako grinned seeing the red hue on her cheek. _Score!_

Sabito made a face to Gudako. "Did you justー"

Gudako cut his sentences with a hush. "Upupup, I'm in the middle of very important task," she said looking at Sabito for a moment before focused back to Makomo.

"Tell me, sweetheart. Is it hurt?"

"Ah... Are you talking aboutー"

"When you fall from heaven. Wanna some help to go back there? I'm pretty skilled doing that."

Makomo's face went as red as tomato. "A-ano..."

Sabito was having none of it. "Okay, stop flirting with Makomo!" He swiftly put himself in-between with annoyed expression. "Tanjirou was right; you really are a woman-eater! Shameless!"

"I prefer 'woman worshipper' but alright, whatever help you sleep at night," With a shrug, Gudako retreated peacefully from her love advance. _It's__ not like I'm in hurry._

"Y'know, since it's almost midnight, I think I need to go back. Demon or not, I'm still enjoying my sleeping beauty andー"

"You haven't answered my question!"

_Hook. _

"Then pray tell, why should I tell about my origin to wandering spirits like you?" Gudako tilted her head cutely. "Before you make accusion, hear me out. First of all, there's no benefit for me. Yes, it will satisfy your curiousity, but what will I get? A simple 'I believe you' bullshit? New flash, mister, you are a wraith. A wandering spirit that couldn't be seen by normies. Kill me? How cute. Can you even possessed anyone?"

"T-that's...!"

"You can't?" Gudako snorted. "That's what I thought. Plus, if I were a normal demon, your beloved master would've been dead. I think that's already a self-explanatory."

"...Tch," Sabito clicked his tongue and turned his head. Gudako couldn't see clearly Makomo's expression, but her lips were thinned into straight line.

_Line._

There was no single remorse in her heart. In fact, Gudako was delighted with their upsetting look. _Mm, mhm! What a good expression__!_

By emotionally cornering them, they would revert to think logically thus easier for negotiating. Coincidentally, miscommunication could happen just because the distinct difference in dialect.

_This gonna be really fun._

"How 'bout this?" Gudako raised both of her index finger. "An eye for eye. Tooth for tooth. I'll tell mine when you're willing to tell yours. Easy right?"

Sabito gave her uncertainty stare. "What's the catch?"

"I'll tell as much as yours. That's the catch."

"..." Both former appretices of Urokodaki stared at each other's eyes, debating in silence. After a moment, Sabito finally gave in and nodded solemnly to Gudako.

"I accept."

Gudako grinned.

"Then let the game begin."

_Sinker._

* * *

In the end, Gudako milked dry Sabito and Makomo without have to reveal wholly about her origin, much to the older man's displeasure.

They only got how Gudako turned into a demon short version, vague description about their first encounter with Demon Slayer, and half-assed explanation why she could maintain her humanity with demon blood running through her veins.

Meanwhile, Gudako got it all. Names of others dying kids, from what era they had been born, who's the oldest and who's the youngest, what demon who had killed them all, and their regret in life. All in precise details.

Sabito really wanted to voice his displeasure, but promise is promise. He ended up blaming himself for being too stupid.

((Sabito considered Gudako's explanation as half-assed because most of it were how awesome Gudako was and her 'mutant gene', or whatever it was.

Technically she wasn't wrong. Her explanation was never vague either. But her poor choice of words, especially her bad habit to use modern time slang ruined it all.

Gudako, for God's sake. You're in Taisho Era, not 21st century era.

Wasn't it too much just for misleading the conversation?))

In other hand, Makomo didn't really mind it.

"Nezuko-dono isn't like other demon, and she loves Urokodaki-sama. That's enough for me."

"Aaaaah!" Gudako clenched her chest in dramatic way. "Angel! God has bestowed angel in front of me! Makomo, I swear by Isthar's ass and Okita's thighs I will definitely find a way to resurrect you and marry you!"

Makomo blushed and cupped her reddened face, utterly embarrassed. "N-Nezuko-dono, p-please don't... But I'm really happy hearing it..."

"CUUUUUTE!"

"STOP IT!"

* * *

When both of them finally got back to the boulder, Ritsuka quickly greeted them with a 90 degrees bow.

"I'm very sorry for my sister," he said solemnly. "She really didn't mean any harm, I assure you. Gudako is just... Like. Uh. That."

Sabito waved his hands flustered. "O-oi, isn't it too much? Stop bowing like that, it's too creepy!" He sighed as Ritsuka immediately straighten back. Honestly, Kamado Sibling were really strange. He started to question their sanity.

"How do you know about our conversation by the way? And, Gudako? I thought her name was Nezuko."

"Gudako is Nezuko's nickname." Ritsuka opened his palm and immediately a small bird landed on it. There was a parchment with strange mark on its head. "And this is Mashu, Gudako's partner. She is the one who told me about it."

"A... Bird? Told you?"

"I can understand Bird's Language."

_Oh. Well._ "How convenient," Sabito commented.

Silence dawned upon them. Three pairs of eyes stared to the moonlight sky, with person held different questions and thoughts.

Sabito peered at Ritsuka curiously. The younger man was staring dazedly at the night sky, burgundy eyes reflecting the thousand stars. The dim light from the moon hit half of his face, created a gentle yet dignified look.

_...Beautiful._ Sabito hid his sigh under his palm.

((Makomo, sensing the change on the atmosphere, quietly left the place with a small smile adorned her face.

Men.))

There were a lot of questions Sabito wanted to ask Ritsuka. Why didn't he cut the boulder now? What made him wait for this long? Why he was very adamant to have a talk with them rather finished his task as fast as possible?

Sabito couldn't understand him. Or rather, he couldn't understand Kamado Sibling. They radiated inhuman power as if they're a walking sun. Sometimes too, they would know too much for one's comfort.

One was too smart and plain Weird with capital 'W'.

One was too powerful and far too kind to be a demon slayer.

Honestly, Sabito started to think that common sense didn't apply on their mind. Or maybe, the common sense itself had been twisted just to fullfil their own need. Either way, he wouldn't be surprised.

The orange haired man was too focused on his thoughts he barely heard someone calling his name. It's Ritsuka.

"Sabito. Can I ask you one more favor?"

The said man stared with dead eyes and said, "If it's about your sister, I'm afraid I have to decline. Sorry."

"What? No, no, no," Ritsuka frantically shook his head. "I just want to ask question, that's all!"

"Alright, alright," with a laugh, Sabito sat a few steps from the boulder followed by Ritsuka. "What do you want to ask?"

Ritsuka was silent for a moment, licking his lips in uncertainty. "...Please," he finally spoke.

"Tell me about Tomioka Giyuu-san. Back in your days."

Sabito went stiff. _Howー?_

As if he sensed his thought, Ritsuka immediately gave him an explanation. "Your yukata's pattern is a dead giveaway. I rarely seen a pattern like that and I doubt I can find it on any store. Yet, Tomioka-san's half of the haori has the very same pattern as yours. Interesting, no?"

"I... I see..."

"Truthfully, the first demon slayer we've encountered is Tomioka Giyuu-san. Not only he willingly spared Gudako's life, he's the one who introduced Urokodaki-san to us."

Ritsuka idly twirled the hem of his haori. "At very least, I want to know more about him. Yet, no matter how many letters I've sent to him, he never replied. Well, I've heard his messenger crow is very old and forgetful, so I'm not... troubled about it."

"..."

"Sabito?"

"...From where do you want to know?"

That night, Sabito thought that Ritsuka's smile was the most beautiful thing he ever seen.

* * *

"Why don't you finish the task now? With your current strengh, you can do it with minimal effort."

"I'm not in hurry. Plus, I want to know more about my other senpai. The least thing I can do to honor them is remembering their name and their deed."

"...I see..."

"S-Sabito? Why are you wiping your eyes that hard? Hey, don't do it too fastーyou're just hurting your eyes now!"

"S-shut it! I'm already dead, things like that won't affect me!"

* * *

A soft knock.

"Urokodaki-san, can I enter?"

A man with tengu mask looked at the standing figure on the door. He nodded.

"Yes, you can, Gudako."

The black-orange colored hair demon took a seat in front of the master of this house. Her left hand clutched a scroll.

"What is it? It's so rare of you to go back when the sun is still up there. What happened?"

Gudako didn't say anything, only gave the tengu masked man the scroll. Urokodaki stared at Gudako for a moment before finally accepted it.

"What's this?" he asked. Gudako hid her green behind the sleeve.

"Just read it, Urokodaki-san, and you'll know."

"..." With a deep sigh, he complied her words.

Gudako closed her eyes and waited.

There was no sound came from both parties. Not even from Urokodaki, although his grip on the scroll was very stiff and his back was hunched as if he's tryimg not to cry.

_T-this__ was..._ With a trembled hand, Urokodaki caressed the engraved words inside of it. _Makomo... Sabito... Everyone...!_

"Thirteen children," Urokodaki paused to look at Gudako. She gave him a small but meaningful smile.

"There are thirteen children currently residing in this mountain. All of them wear a fox shaped mask, and each of them has different details. Yet, because of several reasons, only two of them who has enough power to be seen by certain people: Makomo and Sabito."

Behind the mask, Urokodaki widened his eyes. Thirteen children, all of them wearing fox mask. _Isn't that mean, all of them are myー?_

"Sabito never shut up when telling me the stories of his training back then. Makomo never stop praying for your safety and health. And others, ah, it's better if you just read it out. There's no fun if I narrating it all." Gudako closed her eyes in reminisce.

"Please let me say this to you: you're so loved, Urokodaki-san."

Gudako smiled widely and spoke in cheery voice,

"I'm so glad we can meet someone as awesome as you!"

Urokodaki didn't say anything back. Yet, there was something wet ran through his cheek.

It's tears.

* * *

"Ritsuka."

"Yes, Sabito?"

"Please, for the sake of others children... For our regret and Urokodaki-sensei's grief...

Kill _him_."

Ritsuka stared at the semi-corporal wandering spirit and smiled lightly.

"So the time has come, hasn't it?"

The burgundy haired man unseathed his sword and took a offensive stance in front of the enormous boulder. He steadied his breath and concentrate.

"ーHaaaaaa!"

With a battle cry, Ritsuka swing his arm hard. A loud crack thundered the entire area and debris flew to every direction. In silence everyone present waited patiently for the smoke to clear out before giving him the final verdict.

A strong gush came sweeping all of the debris and dirt, giving them a clear view.

The boulder had splitten perfectly into two.

Last task: finished. He was now allowed to join Final Selection.

Ritsuka couldn't help but feeling proud.

He didn't look back when Makomo went back into the wood, become one with the foggy environment. Nor when Sabito patted his shoulder and followed Makomo's step.

_I swear I'll avenge you all_.

The demon hand wouldn't know what kind of ending that would befallen upon him.

**Notes for the Chapter:**

> For some reason my mood writing this chapter mainly came from me writing my other fanfic. It's called Vigilant Spider if you're wondering, MCU x KHR fic
> 
> Yea what the heck im thinking about, writing two different fanfic in the same time.
> 
> By the way. About the strange aura. The thing that Sabito sensed it's actually Gods and Goddesses' blessing. Because it came from different reality, he didn't recognize the divinity aura. Especially since both Gudako and Ritsuka previously an active mage, anyone who had a strong sense of supernatural world (like spirits for example) would sense their anomaly existence. 
> 
> In short: Ritsuka and Gudako is in Ultra Instinct mode forever.


	8. Chapter 8

**Summary for the Chapter:**

> Kamado Siblings wondered how the fuck Shinjurou could produce two cinnamon rolls like Kyojurou and Senjurou. 
> 
> In the same time, Gudako wasn't amused with how parents in Taisho era named their own children. Like, come on. Laaame.
> 
> Sadly Kyojurou didn't think the same. Pity.

**Notes for the Chapter:**

> Obligatory the premature bud of Kyojurou/Tanjirou. I thrist for this and fkskkfskdkb I can't make decent romance tension like a normal being

"So your name isー_munch_ーSenjurou, eh? And yourー_munch_ーfather's nameー_munch_ーis Shinjuー_munch_ーrou? Wow, talk aboutー_munch_ーuncreative."

"Gudako, your manners..."

She only spared him a glance then her munch went intensified.

Ritsuka stared nervously to the gawking figure on his front. He felt a little bit sorry for showing this side of Gudako to Senjurou. Look at the poor boy, he clearly didn't know how to react properly.

_But I can't fully blame her though,_ Ritsuka hid his suffering sigh and maintained his professional smile as his eyes met with the second figure accross the room. The said figure only glared back, but his main point wasn't him rather the one who sat beside Ritsukaーit's Gudako.

_Shinjurou is a total bastard, of course Gudako would act indecently to make him mad. Oh hey, it's rhyme. _

Their first meeting with Rengoku Shinjurou wasn't good at allーand if they have to admit, it was the worst first impression ever they had in this second life. Ritsuka barely held himself to not headbutt the rude man and let Gudako's negotiate skill worm their way to enter the house.

Gudako gave Ritsuka a look with a finger lifted up. He stared blankly at the awaiting hand. With a sigh, Ritsuka stealthy scooted closer and placed his opened palm beside her thigh. Gudako swiftly relayed her message by hiding their hands under long kimono sleeve. She adjusted it so it was on Shinjurou and Senjurou's blind spot.

_Rengoku __Shinjurou__. Former Flame Pillar and the father of Rengoku __Kyoujurou__ and Rengoku __Senjurou__. A man with inferiority complex. Tended to act first and think second. Whipped as hell to his late wife, Rengoku __Ruka_. _The voice of reason in this family._ _A total bae. Black haired Goddess. Dead mom ponytail. 10/10 would bang her. 100/10 will let her bang me. Kuudere. BAMF. She can step on me and I'll thank her for her generosityー_

Her finger movement halted as Ritsuka harshly pinched her palm.

_Focus_. _I don't need to hear you thrist over a_ married woman.

Gudako bit her tongue to stop the wince went out from her mouth. _Tch. No fun. _

_ーA hardheaded tsundere, although there's almost no __dere_ _after his wife died. Hard to convince that you are worthy to be Rengoku's_ _tsukugo__, but not impossible. Personally I don't think you need his recognition. He deserves a hard kick on nut. __How he could produce angels like Senjurou and __Kyoujuro__ is baffling me.__ Previously, he was aー_

"Um,"

Gudako stopped her track to focus at the young man in front of her. He was sweating bullets, visibly nervous to talk with the newest tsuguko of his big brother. Most probably because Kyojurou made his decision without even noticed his family, so he was in shock when his supposedly romantically naive big brother brought another man to their house. _Aw, poor guy. He's trying his best. __Ganbatte_ _otouto__-kun__!_

((No. There wasn't any correlation between Kyojurou's cluelessness about romance and the fact that he brought Ritsuka (and Gudako) to his home.

Goddammit Gudako, stop messing around with the narration.))

"Is the tea on your liking..." Senjurou eyed his ever-smiling brother for a moment before continued, "Ritsuka...san? Is it alright if I call you that?"

"It's alright, you can call me whatever you want," replied Ritsuka with reassuring smile. He caught Gudako's hand firmly before she could write anything weird on his palm without even looking. Veins popped on Gudako's temple as she tried to free her hand from Ritsuka's tight clutching.

All's happened under her kimono's sleeve.

Kyojurou, who sat in perfect angle to have perfect view of Kamado's sibling interaction, contemplated very hard whether he had to address their... hand fighting(?) or not. He decided not to. Kyojurou had long accepted that his new tsuguko had quirky sister that it's the best for him to not force himself to understand her. It's better to keep silent and observe where the situation going.

A thought popped on his head. _Ah, right, I need to address this to Father. _

Shinjurou's first impression for Kamado sibling wasn't very great, if Gudako's deliberately bad manners was any indication. But to be honest Kyojurou didn't expect much. Although he had been a honorable man once, it was all changed when his mother fell into incurable sickness and thus died. Since then, Shinjurou was no less than bitter man who lived just to spit on cruel worldーin literal way.

"Father," he spoke in unwavering tone. "I'm picking Kamado Tanjirou-kun as my tsuguko. For that, I want toー"

"No," Shinjurou growled as he slowly stood up. "I don't agree with you. You want thisーthis mockery to our family's fire breath become your tsuguko? You do?!"

He took a big gulp of alcohol before continued, "Kyojurou, just stop this nonsense! You want to make shame of your weak self by having thisーthis Sun Breath user as your tsuguko? Have you no shame at all?"

Before he could do anything, Gudako immediately threw her lukewarm tea to his face. Her face was void from emotion.

She was very fed up with Shinjurou's bullshit. Their first meeting had left a bad taste on her mouthーwhat kind of father he was, mounting off his own son after finished a life-threatening mission? Insulted his brother for having unique mark and hit him out of unadulterated anger? Punched the sweet boy like Senjurou and _fucking ripped_ his own family legacy like it was nothing?

She was so _done_.

"Old man," Gudako spoke. "I don't care if you are suffered with inferiority complex. I don't care if you don't like our family's Fire God Breath. And I utterly don't give a fuck if you're just an overgrown sad boi who still can't accept that your bae died, thus you have to protect your kids for her behalf. But one thing I have to tell you,

No one, and I mean no _fucking_ one, can insult Rengoku-san and my brother's competency! And what do you actually know about Ritsuka you pathetic, edgy as hell, overgrown sad boy? You wanna fight, dude? You wanna fight? Then fight it is!"

Ritsuka stared in horror as Gudako let her claw out and her hairs started to defy gravity. Senjurou screamed.

"Gudako, stop it you absolute dumbassー"

Veins popped on Shinjurou's temple. "That cat-like pupils, you're a demon!"

Kyojurou calmly pulled terrified Senjurou to his back and retreated to the corner of the room.

Ritsuka was still stood between the enraging duo, tried his best to stop his sister at all cost.

"Goddammit Gudako stop itーdon't you dare pull me back, you dolt! Oi, you hear meー"

"Don't fuck with me! I have the power of God and Anime on my side!"

"Gudaー"

"AAAAAAAAAAAAAAAAAA!"

* * *

"I'm sorry."

Ritsuka performed a perfect dogeza in front of two heirs of Rengoku clan, with Gudako mimicked his action beside him. A big lump rested on top of her head, creating a comical sight.

Meanwhile, Shinjurou had been safely evacuated to other room. He was currently in the middle of fainted state, harboring tons of scratches and a lump on his temple created by a certain hard-headed guy.

The said guy was now still in kowtow position, firmly ignored the panicked voice from the younger one of Rengoku brothers.

"R-Ritsuka-san! You don't have to!"

"Nonsense," replied Ritsuka not even got up from his kowtow position. "I'm still one to blame since I let him trash talk and invited Gudako's anger. I'm so sorry on behalf myself and my sister. Gudako, you too."

"Forsooth, I humbly beseech thee to forgive my most grievous transgression."

_Not in english, you son of aー_

Her apology was not genuinely at all. Of course, of course. Ritsuka didn't even need to see their face to know how confused the Rengoku brothers. He was now felt ashamed beyond belief.

Ritsuka had to bit his lips to make another witty remark. _Calm, myself. It's Gudako. Gudako never regret her action, so what do you expect? Calm down, calm down. _

_Breath. In. Out. In. Out. In. Out._

Ritsuka pressed his temple harder to the mattress and ask for apology once more, much to Senjurou's chagrin and Kyojurou's exasperation.

Flame Pillar's newest successor, people.

* * *

Thanks to Ritsuka's unlimited patience and Gudako's superb skill in negotiation, they successfully won over Shinjurou's recognition as Kyojurou's successor and unusual demon. Not that they saw it as achievement worth to celebrateーthat man was a total tsun, and luckily they knew _very_ well how to charm a hardcore tsun like him.

Never underestimate Protagonist Skill level EX.

In another hand, Ritsuka had a field day bonded with Rengoku brothers. Kyojurou's enthusiasm somehow reminded him with Leonidas. Although his enormous appetite rivaled Altria and her infinite copies.

Meanwhile, Senjurou was a breath of fresh air. He never had a younger brother figure, and back in Chaldea the closest figure he could find was Ko-Gil and Paris. But Paris was more or less a, uh, trap, and Ko-Gil was not the best example of 'docile younger brother'. After all he was, undeniably, a Gilgamesh. No matter how he denied to be the same as his adult self.

Hans Christian Andersen was...not a child. He was a gremlin with Ozy's voice. His appearance was undeniably adorable though, there's times where Ritsuka couldn't help but treated him like a child.

Look at him; he's so small like an actual child! His materーI mean, paternal instinct couldn't help but screamed to spoil him rotten.

((_**Hey**_, there was a small voice whispered in the back of his head.

_ **What about ** _ ** _T̷̢̡̰̟̙͎̙̩͕̩̻͍̣̞̄̅́̃͒̈́̈́͑͝͝ä̵̢̨̘̞̻̮͉̼̮̠̬̪́̊̽̈͘̕͜͠k̸̻̺͎̈̏̽̋̇̔̐̅͒e̶̡̢̼̗͔̥̝̙͒͆̇͂͐͂͝͝͝õ̵̖̯̟͌̾̇̓̂̕͝͝͠?_ **

_ **S̷̢̱͍̱̯̘̾͊͊͆ĥ̴̺̝̗͚͜i̸̛͓̳̊̕g̸̤͉̱̾͊̆͜e̵̝̔̐̓r̵̩̩̣͈͊̚ù̴̻͖̯͕̟̣̟?** _

** _Ȑ̷͔̘̈͑̂̉̑ǫ̷̧͇̜̖̗͓̻̒̊k̴̛̛̹͎̯͕̪̉̾̈́͂̄̏ũ̸̺͎͍̔̇̐ṫ̷̨̫̱͉̣͇̺̑̃å̸̻̳̜̫͚̲̌̅͛͂͑?_ **

_ **Wh** _ _ **at about ** _ _ **Ḥ̸̺͉͎̠͇̠̲̓̉͝ȁ̴̡͇̺̤̜͓̀͆͌̾̓́͊̋̕͠n̵̨̙̙̹͙̖̋͊̿̋̃̚ą̷̧̖͓̣̫̟͚̗̣̓̂̍͒̋̓͑͘͜k̴͍͍͍͔͆͛̿͊͋o̷̡̗̺̱̗̹͕̱͑͐̎̉?** _

_ **...** _

_._ _.._

_They're,_

_..._

_They're Kamado Tanjirou's siblings._

_ **...** _

_Not mine._

_..._

_Not Ritsuka's._ ))

_ーOkay, stop with the flashback. Focus, focus. _

Ritsuka let out a deep breath and stood from his seiza position. He couldn't meditate with distraught head; pulling off some steam might help him clear his mind.

_Should I practice a new form? Or maybe I should try using other weapon?_ Ritsuka hummed as he twirled his wooden sword. _Spear sounds good... I wonder if there's a slayer using __naginata__._ _Or maybe I canーhm?_

He glanced at unused pile of uncut bamboo accross the garden. If he remember correctly, Kyojurou had intended to make _nagashi_ _somen_ but had difficulty finding the right size for the pipe. He kept bringing back home the one he deemed decent over and over until he finally found the right size.

And thus, a big pile of uncut bamboo was born. All in different thickness and size, already cleaned up and safe to meet bare hands.

_Hmmm._

Ritsuka picked one of them. It's one of thin bamboos t hang the laundry and make poles. It had good durability and its length at least twice of his arm.

_Hmmmmm_ _._

_Eh, it's just venting off some steam. A piece of bamboo will be suffice._

* * *

Today was a good day.

The sky was clear, yet not blazing hot. The white cloud rolled around almost lazily, gave anyone who gazed upon them a wonderful sight. The wind outside felt really pleasant too; it's comforting and not dry at all. Together with the sounds of rustling leaves and chirping birds, it brought nothing but joy to those who listen to their song.

In conclusion: it's a perfect time to relax after serious meeting.

Kyojurou nodded to himself as he walked to the open room that faced his home garden. He had just gotten back from another pillar meeting; mainly they were talking about the movements of Upper Moon and the surprising lack of Lower Moon Demon. So far their only lead was a rumour saying that an Upper Moon currently resided in red light district. Uzui Tengen, the Sound Pillar, had sent his wives to be his eyes and ears. Further information must be awaited until next time.

The current situation was slowly became tense, but Kyojurou felt pretty optimistic. After long years without any sight of Twelve Moon Demons, in span less than one year, two Lower Moon had been slayed and one Upper Moon had appeared on their sight. Furthermore, someone had encountered Kibutsuji Muzan face to faceーa Kinoe-rank slayer, no less!

Although the said slayer was now his cherished tsuguko, who also the one slaying the reported Lower Moons. There's no official report about the length of his true strength, but Shinobu Kochou had reported that Kamado 'Ritsuka' Tanjirou might be the last person who used the original style of the most famous swordsmanship in Japan, Niten Ichi-ryū.

_"It's like watching a divine art," Shinobu sighed dreamily and cupped her cheek. "Two swords contemplating each other. When he swung his sword, it's like impossible become possible. I can't sense anything from his blade: no anger, no passion, no killing intent, nothing. It's simply void of earthly desires, void of mortal emotions._

_Fufu, I felt like just had witnessed a history being remade." _

The meeting instantly took a sharp U-turn. Shinobu Kochou wasn't that kind of person who would exaggerate things, much less telling lies. Especially when reporting to Oyakata-sama himselfーthat man knew his children very well, so lying would be futile.

Oyakata-sama was very excited hearing it, even vocally said he wanted to witness it when there's opportunity. In other hands some pillars expressed their skepticism but didn't press any further. Everyone knew better not to invite infamous Insect Pillar's fury. Kamado might no longer the residents of Butterly Estate, but they still came over pretty often and the kids love those two dearly.

Plus, it's dangerous to anger their only capable healer, who coincidentally also a poison master. Make a mistake, and God knew what would she added to their meal.

Kyojurou personally never doubted Shinobu. With their daily sparring, the Flame Pillar slowly got a glimpse of what his newest tsuguko capable of.

At very least, he could agree that Tanjirou was strong. Far stronger than him even, when Kyojurou was in his age. He had no fixed attack pattern thus making him unpredictable, and didn't shy away from using fists and foot. One time he would use Water Breath Techniques, then suddenly it changed to Flame Breath Techniques, followed by a punch in gut, then he ended it with Breath of Fire God Techniques.

It was an overwhelming defeat. If there's a hole, Kyojurou wanted to enter it.

And as if he wasn't deadly enough fighting alone, his team-up with Nezuko was a straight subjugation.

Kamado 'Gudako' Nezuko. A woman with, pardon his language, screwed up head and colorful profanities he sometimes wondered where she had learned all that words. Like her brother, she was too accustomed with her nickname she sometimes forgot her real name. Hence why Kyojurou determined to call both Kamado Sibling by their real name so they wouldn't forget about it.

Nezuko was clearly not a physical fighter, rather she was a tactician. Her demeanor and they way she brought herself screamed it so. Similar to Oyakata-sama, she fought with her wits and commands. She's the one who would unravel all weakness of their foe in one sitting, and used all of the opportunities to make everything played on her tiny palms. Combined with her chaotic nature and ambiguous action, she was completely unreadable except to her own brother. It was pure coincidence that she was turned into a demon, thus granted her an unparalleled strength. With her current body, she could leisurely kick an adult grown up into oblivion.

One time Kyojurou thought he would've lost his life if he were one second late dodging Tanjirou's strong kick.

The other time Kyojurou was _very_ _sure_ he would've lost his ability to continue Rengoku's bloodline if he hadn't stepped away from Nezuko's punch.

While their dynamics could be seen as an act of knavery, Kyojurou saw it as an act of survival.

They were demon slayer, which only meant other people's lives and their own rested on tip of their blade. No one care if they died in honor or for protecting your pride; if those innocent lives died because of one's selfishness, then they're no better than heap of scum. Even those who died in dishonor would be regarded highly if their intention was pure.

Although, Kyojurou wished Tanjirou could stop targeting his lower body parts when throwing kicks and punches. While it was a good practice, he didn't even want to imagine what if his junior got hit.

Ouch.

_U-umu__,_ Kyojurou gulped down his growing nervous. _I should tell this to Tanjirou-shounen. Now, where he is right nowーhm?_

When Kyojurou entered the room, his ears caught a faint sound from the garden outside. It's a sound of something was swung in fast pace, but it's not a wooden sword. It was something... thinner.

_It must be Tanjirou,_ he thought, silently approached the source of the voice. Kyojurou was sure there's no one beside him within this house. Senjurou was currently with Nezuko, went to Butterfly Estate to learn about basic health treatment and first aid. His Father at this time of day was wandering to somewhere else againーprobably to buy alcohol. 

_But I thought I've told him there's no sparring today. What is he doing? For heaven's sake, being a battle junkie is fine, but your body needs a break too!_ I thought you knew better than... this...

_...this isー?_

Kyojurou stood agape at the sight. At the center of the garden, there was Tanjirou practicing a form of seemingly martial art with a long piece of bamboo as his main weapon. By how he kept thrusting the tip of bamboo in remarkable speed, he guessed it must be a spear-oriented martial art. He slowly sat down and focused his gaze on Tanjirou.

It's not weird to be proficient in multiple martial art forms, but it's quite rare nowadays. They either became a jack of all trades but master of none, or mastered them all with time as the cost.

But again, he was talking about Kamado Tanjirou, the actual prodigy of his era. A strong swordman that had unlimited potential in his pocketーeven if the person himself didn't realize it.

_...is it a normal martial art, though?_ Kyojurou cocked his head in confusion. There's no usual elegance one can find spearmanship, but it has their own charm in strength matter.

He might had no vast knowledge about spearmanship, but her mother was capable of fighting by using naginata. When he was still young, there were times his mother had a light spar with his father. While he couldn't remember clearly now, he could tell the spearmanship Tanjirou currently use was far different than his mother's.

It was... deadlier. Focused more on speed and brutality. Each trust promised unbearable pain and strong intent to kill. It's a cruel style that focused on weakened the foe first and granted them death second. Kyojurou couldn't hold back his shudder when he realized Tanjirou only targeting human's lower body part, mainly where the jewel of every man alive residue.

_ーno, no,_ Kyojurou shook his head hurriedly. _He may be pictured four legged animal as his opponent, like boars or tiger. Not human. Not a man. Not a crotchーalright, stop thinking about it!_

He let out a suffering sigh. No matter what, it seemed he couldn't get the last practice match with Kamado sibling out of his mind. Especially when Nezuko almost busted his crotch while screaming _"Polygamist__ Castration Fist!"_ with all of her might. It had been days, yet he just couldn't forget the horror.

((Kyojurou had a feeling she had treated their last fight as a test for her newest fist style, but he didn't press it further. He didn't want to make himself as target practice.

Polygamist Castration Fist. What a scary technique.))

With another head shake, Kyojurou snapped from his musing and went back to observe his only tsuguko more. When he ignored its brutal imaginary picture he kept getting, he had to admit it was eye-catching and beautiful in its own way. The way his spear synergies with his body, strucked hard and fast without mercy, and how his body twisted and thrusted, full of determination and no will to lose...

If there's a doubt about him killing Lower Moon Five singlehandedly, it would be instantly washed away.

_Astounding, _he praised. _Truly astounding! With this level of strength, you may become a pillar anytime sooner! I'm surprised Oyakata-sama hasn't offered you the position; maybe I should mention this in the next meeting!_

Kyojurou smiled brightly at the idea. As he himself was still on his peak, he knew Ubuyashiki wouldn't force him to enter retirement. Most probably he would assign Tanjirou another name, or let him shouldered the 'Fire' pillar name, making both of them the Flame Pillar. And to make it way cooler, he would use his exquisite spearmanship in demon subjugationーlike the infamous Dragon of Echigo, Uesugi Kenshin.

No, Kyojurou absolutely didn't know whether it was possible or not, but a man could dream right? Especially when he had been treated by such sight.

_Umu_, his eyes went softer as he gazed at the sight.

_It's truly beautiful. _

He wasn't talking about the spearmanship.

**Notes for the Chapter:**

> Ritsuka's teacher in spearmanship is Scathach. That's why his spearmanship focused more on effectiveness and brutality.  
Ritsuka spooning Hans in sleep is canon. It's on the FGO demo PV. 
> 
> I personally didnt think Oyakata-sama hadnt offered the pillar position to Ritsuka, considering he had slayed a Twelve Moon Demon all alone. It's Ritsuka who refused the position. His reason was because he didn't want to make a bigger distance with his friends, plus he was currently the only slayer who was keeping a demon. If he had raised into a pillar in such unbelievable pace, it would invite unwanted rumours about Demon Slayers Corps. 
> 
> Btw i need chapter 185. Wheres chapter 185 spoiler where is it wheRE IS IT WHERE IS IT WH E R E


	9. Chapter 9

**Summary for the Chapter:**

> Ubuyashiki finally got a chance to have a talk with the infamous "demon".

**Notes for the Chapter:**

> Kinda...foreshadowing. Kind of? I think?

"I thank you for saving Rengoku, Kamado Nezuko-dono. Or perhaps, are you prefer to be called as Gudako?"

Gudako calmly sipped her tea, creating a picture of elegance and composure. "This humble one doesn't worthy for your thanks, Oyakata-sama. I simply did what I can do to support the team," she said.

"And I do not mind any names, although I do prefer to be called as Gudako. No suffix needed."

"Is that so?" Ubuyashiki hid his amused smile with his sleeve. After all of the rumours, their first meeting, and information he got from the pillars, he didn't expect for her to be able behaving in such polite manner. It's as if he was talking to different person. Ubuyashiki had believed he had known every single aspect about his children, but it seemed the reality had planned one step away, like always. 

Maybe she had another agenda?

Not impossible. Kamado Nezuko, or Gudako since she wanted to be referred with that name, had showed her extraordinary wits countless time. Many lives had been saved and unnecessary disputation had been avoided.

And the scary part was, never she was directly involved nor expressed her true intention in any ways possible. She simply pulled the string, played a jester role, and fooled everyone to make them think that their action was 'unexpected'. That their choice was purely came from their own intention.

In reality, it's the opposite. Always the opposite.

With such cunning brain pulling strings behind his back, Ubuyashiki couldn't help but getting curious. What did she plan? Would it beneficial for Demon Slayer Corps? Or would it put Muzan in advantageous spot?

Playing mind games with the girl in front of him was like man who had been playing shogi for years challenging a professional shogiーwhile he might as well put some fight or even cornered her down, she would find a way to defeat him again and again.

Plus, using such method to his own child left a bad taste on his mouth. He loathed it.

Ubuyashiki just wanted to know. He wanted to know what's inside the girl's head whose existence was an enigma and see if it could put their endless battle with Kibutsuji Muzan into an ending.

Ubuyashiki Kagaya truly, truly wanted to know more about her and her sibling whose future couldn't be predicted no matter what. Or rather, he wasn't allowed to see it.

It was intriguing to say at least. Why he wasn't allowed to see it? How powerful their guardian spirit was to the point able to make a affect in reality?

Was it related to Kamado siblings' unwillingness to be referred by their true name? After all, when one changed their name deliberately, it meant that they'reー

"With all due respect, I advise you to stop trying to figure me out, Oyakata-sama. Or else your head will explode."

Ubuyashiki blinked at the deadpanned girl. Was she able to read his thought? "My apologies," he said. "I do not mean to pry into your personal life. I'm just, ah, curious. On the side note, this is my first time hearing that idiom. Is it something you made by yourself?"

Much to his surprise and slight amusement, Gudako made a choked noise. He might had lost ability to see, but he could imagine the horror look on hher face before it disappeared quickly. Her breath sounded controlled in rhyntm, most probably she forced herself to stay calm.

Huh. Interesting.

"Please do not mind it," she said, deliberately coughed on her fist. "Anyway, you don't have to concern yourself with mine business, Oyakata-sama. I am well aware with your worry, and I shall assure you I will never, ever put anyone in danger."

Gudako fixed her expression and spoke in strong intensity, "My goal is to protect everyone. You shall have my word."

She went silent for a moment before added, "Of course, except those who deserve it. I'll make sure to put them in big danger."

A silence dawned upon them for a moment.

"...Fufu," Ubuyashiki couldn't help but laughed. While the way she wording her sentences sounded arrogant and impolite, he could feel the confidence and strong determination. It wasn't something that can be pulled off with a mere will of revenge or bloodlust. As a tactician, vowed to protect everyone meant she couldn't make a mistake in her decision, nor bothered with unexpected situation. She must be cool-headed all the time, thinking outside of the box, and put all of her faith to her comradesーwhose very life depended on her command and decisions.

It was the safest, yet most nerve-wracking job to handle. There's no room for doubt nor negative emotion; not until lives had stopped falling down like a rain and sun finally showed its light after a long storm.

When the fight had finally met its end, that's the time when all tension evaporated and one finally allowed to grieve.

((It's not easy to be the one who sat in the back line while their friends, their family, their comrades ran to the front line just to lost their fragile life forever.

And they couldn't do anything, could only watch in silence and commanded other people.

It's never easy.))

"I believe you," he spoke with gentle smile adorned his rotted face. "It is such a shame I no longer have the ability to see. I really wish to witness your deed in the future..."

"Believe me, you'll be disappointed," Gudako muttered under her breath.

"Amane," Ubuyashiki called her wife who stayed silence beside him. "Can you tell me what time is it now?"

"The sun has started to set," Amane said. "A hour and half before the night come."

"I see. Thank you, Amane," he said. "Once again, thank you for coming here, Gudako, even though you're just finished accompanying Senjurou-kun's training."

"No, no. I'm the one who should thank you. This humble one is not one of your children, yet you treat me like your own. You even ask for a private talk with me, a demon, in your house no less. This humble one is so honored for such kind treatment."

"Such nonsense," he replied back. "You're my children too, Gudako. You may not an official member of Demon Slayer corps, but your deed has saved many lives countless time. I can't thank you enough for everything you have done for our organization."

"..." She didn't say anything, expression remained unreadable.

Ubuyashiki felt like there was something left unsaid, but he didn't push it. He kept smiling as Amane whispered that Gudako was leaving.

_What a mysterious sibling_, Ubuyashiki thought to himself after Gudako had left their household. _This is my first time I can't figure someone out completely._ His instincts, the ability that had been passed from one generation to next in Ubuyashiki lineage, had rendered useless beyond belief.

Wait. If he remembered correctly, there was term that could described their existence. A foreign term hailed from faraway land, coined by a man of wisdom. Described as a device that put tragedies into an ending, albeit too sudden and unexpected. One could even accuse it as underhanded trick, or a theater play that has strayed away from harsh reality. If he wasn't mistaken, the correct term was...  
  
  
  


_Deux_ _ ex machina._  
  


Roughly translated, from God to machine.  
  


_God, huh?_  
  


_...How funny. _

Ubuyashiki then chuckled, inviting his wife's curiosity. 

"What are you laughing for?"

"Ah, nothing," yet he still chuckling.

"It's nothing important."

* * *

It's really funny,

For the fact that those term perfectly described Kamado Sibling's existence: two beings that had brought nothing but raging storm to their stagnancy, like Apostles of God descended to Mortal world to put endless tragedies into an end.

Ubuyashiki couldn't deny how ridiculous how it sounded. But, with how little information he could gather and mysteries that always lingered around Kamados'... Even a sane mind could be swayed too.

_Probably_, he wondered.

_Probably, it explained why they have refused using their real name._

Because, when one threw away their original one,

It meant they had chosen to take life-changing path,

or,  
  
  
  
  
  
  
  
  
  
  
  
  


They had chosen another identity to bear over.

**Notes for the Chapter:**

> Take an extra care with how Gudako promise big bad pain to "those who deserve it". Question: are all demon deserve the big bad pain? Are all human deserve to be saved?
> 
> Ambiguous morale is my k i n k

**Author's Note:**

> may added another chapter if needed


End file.
